diff --git a/gulpfile.js b/gulpfile.js
index 108ab62..f2cc603 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -2,6 +2,7 @@ const { dest, watch } = require('gulp');
 const ts = require('gulp-typescript');
 const fs = require('fs');
 const path = require('path');
+const sourcemaps = require('gulp-sourcemaps');
 
 const tsProject = ts.createProject('tsconfig.json');
 
@@ -29,8 +30,10 @@ function tsc() {
 
   return tsProject
     .src()
+    .pipe(sourcemaps.init())
     .pipe(tsProject())
-    .js.pipe(dest('dist'));
+    .pipe(sourcemaps.write('.', { sourceRoot: './', includeContent: false }))
+    .pipe(dest('dist'));
 }
 
 exports.tsc = tsc;
diff --git a/package-lock.json b/package-lock.json
index 5d22e5d..52cebce 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -24,24 +24,101 @@
         "js-tokens": "^4.0.0"
       }
     },
+    "@gulp-sourcemaps/identity-map": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/@gulp-sourcemaps/identity-map/-/identity-map-1.0.2.tgz",
+      "integrity": "sha512-ciiioYMLdo16ShmfHBXJBOFm3xPC4AuwO4xeRpFeHz7WK9PYsWCmigagG2XyzZpubK4a3qNKoUBDhbzHfa50LQ==",
+      "dev": true,
+      "requires": {
+        "acorn": "^5.0.3",
+        "css": "^2.2.1",
+        "normalize-path": "^2.1.1",
+        "source-map": "^0.6.0",
+        "through2": "^2.0.3"
+      },
+      "dependencies": {
+        "acorn": {
+          "version": "5.7.3",
+          "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.7.3.tgz",
+          "integrity": "sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw==",
+          "dev": true
+        },
+        "normalize-path": {
+          "version": "2.1.1",
+          "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-2.1.1.tgz",
+          "integrity": "sha1-GrKLVW4Zg2Oowab35vogE3/mrtk=",
+          "dev": true,
+          "requires": {
+            "remove-trailing-separator": "^1.0.1"
+          }
+        }
+      }
+    },
+    "@gulp-sourcemaps/map-sources": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/@gulp-sourcemaps/map-sources/-/map-sources-1.0.0.tgz",
+      "integrity": "sha1-iQrnxdjId/bThIYCFazp1+yUW9o=",
+      "dev": true,
+      "requires": {
+        "normalize-path": "^2.0.1",
+        "through2": "^2.0.3"
+      },
+      "dependencies": {
+        "normalize-path": {
+          "version": "2.1.1",
+          "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-2.1.1.tgz",
+          "integrity": "sha1-GrKLVW4Zg2Oowab35vogE3/mrtk=",
+          "dev": true,
+          "requires": {
+            "remove-trailing-separator": "^1.0.1"
+          }
+        }
+      }
+    },
     "@types/anymatch": {
       "version": "1.3.1",
       "resolved": "https://registry.npmjs.org/@types/anymatch/-/anymatch-1.3.1.tgz",
       "integrity": "sha512-/+CRPXpBDpo2RK9C68N3b2cOvO0Cf5B9aPijHsoDQTHivnGSObdOF2BRQOYjojWTDy6nQvMjmqRXIxH55VjxxA==",
       "dev": true
     },
+    "@types/jsdom": {
+      "version": "12.2.3",
+      "resolved": "https://registry.npmjs.org/@types/jsdom/-/jsdom-12.2.3.tgz",
+      "integrity": "sha512-CxYWGFsBs0VZ/lU9zxfWk7zYfOlQQuSs5yzk34KW/vQQJGE8OGOYxJnqj9kGHE1SBZGVJvhXs1TafIpZL8RvXw==",
+      "dev": true,
+      "requires": {
+        "@types/node": "*",
+        "@types/tough-cookie": "*",
+        "parse5": "^4.0.0"
+      }
+    },
     "@types/node": {
       "version": "8.10.49",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-8.10.49.tgz",
       "integrity": "sha512-YX30JVx0PvSmJ3Eqr74fYLGeBxD+C7vIL20ek+GGGLJeUbVYRUW3EzyAXpIRA0K8c8o0UWqR/GwEFYiFoz1T8w==",
       "dev": true
     },
+    "@types/node-fetch": {
+      "version": "2.3.7",
+      "resolved": "https://registry.npmjs.org/@types/node-fetch/-/node-fetch-2.3.7.tgz",
+      "integrity": "sha512-+bKtuxhj/TYSSP1r4CZhfmyA0vm/aDRQNo7vbAgf6/cZajn0SAniGGST07yvI4Q+q169WTa2/x9gEHfJrkcALw==",
+      "dev": true,
+      "requires": {
+        "@types/node": "*"
+      }
+    },
     "@types/tapable": {
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/@types/tapable/-/tapable-1.0.4.tgz",
       "integrity": "sha512-78AdXtlhpCHT0K3EytMpn4JNxaf5tbqbLcbIRoQIHzpTIyjpxLQKRoxU55ujBXAtg3Nl2h/XWvfDa9dsMOd0pQ==",
       "dev": true
     },
+    "@types/tough-cookie": {
+      "version": "2.3.5",
+      "resolved": "https://registry.npmjs.org/@types/tough-cookie/-/tough-cookie-2.3.5.tgz",
+      "integrity": "sha512-SCcK7mvGi3+ZNz833RRjFIxrn4gI1PPR3NtuIS+6vMkvmsGjosqTJwRt5bAEFLRz+wtJMWv8+uOnZf2hi2QXTg==",
+      "dev": true
+    },
     "@types/uglify-js": {
       "version": "3.0.4",
       "resolved": "https://registry.npmjs.org/@types/uglify-js/-/uglify-js-3.0.4.tgz",
@@ -252,6 +329,12 @@
       "integrity": "sha512-NuHqBY1PB/D8xU6s/thBgOAiAP7HOYDQ32+BFZILJ8ivkUkAHQnWfn6WhL79Owj1qmUnoN/YPhktdIoucipkAQ==",
       "dev": true
     },
+    "abab": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/abab/-/abab-2.0.0.tgz",
+      "integrity": "sha512-sY5AXXVZv4Y1VACTtR11UJCPHHudgY5i26Qj5TypE6DKlIApbwb5uqhXcJ5UUGbvZNRh7EeIoW+LrJumBsKp7w==",
+      "dev": true
+    },
     "abbrev": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
@@ -270,12 +353,28 @@
       "integrity": "sha512-d3OEjQV4ROpoflsnUA8HozoIR504TFxNivYEUi6uwz0IYhBkTDXGuWlNdMtybRt3nqVx/L6XqMt0FxkXuWKZhw==",
       "dev": true
     },
+    "acorn-globals": {
+      "version": "4.3.2",
+      "resolved": "https://registry.npmjs.org/acorn-globals/-/acorn-globals-4.3.2.tgz",
+      "integrity": "sha512-BbzvZhVtZP+Bs1J1HcwrQe8ycfO0wStkSGxuul3He3GkHOIZ6eTqOkPuw9IP1X3+IkOo4wiJmwkobzXYz4wewQ==",
+      "dev": true,
+      "requires": {
+        "acorn": "^6.0.1",
+        "acorn-walk": "^6.0.1"
+      }
+    },
     "acorn-jsx": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/acorn-jsx/-/acorn-jsx-5.0.1.tgz",
       "integrity": "sha512-HJ7CfNHrfJLlNTzIEUTj43LNWGkqpRLxm3YjAlcD0ACydk9XynzYsCBHxut+iqt+1aBXkx9UP/w/ZqMr13XIzg==",
       "dev": true
     },
+    "acorn-walk": {
+      "version": "6.1.1",
+      "resolved": "https://registry.npmjs.org/acorn-walk/-/acorn-walk-6.1.1.tgz",
+      "integrity": "sha512-OtUw6JUTgxA2QoqqmrmQ7F2NYqiBPi/L2jqHyFtllhOUvXYQXf0Z1CYUinIfyT4bTCGmrA7gX9FvHA81uzCoVw==",
+      "dev": true
+    },
     "ajv": {
       "version": "6.10.0",
       "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.10.0.tgz",
@@ -460,6 +559,12 @@
       "integrity": "sha1-p5SvDAWrF1KEbudTofIRoFugxE8=",
       "dev": true
     },
+    "array-equal": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/array-equal/-/array-equal-1.0.0.tgz",
+      "integrity": "sha1-jCpe8kcv2ep0KwTHenUJO6J1fJM=",
+      "dev": true
+    },
     "array-find-index": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/array-find-index/-/array-find-index-1.0.2.tgz",
@@ -615,6 +720,12 @@
       "integrity": "sha512-z/WhQ5FPySLdvREByI2vZiTWwCnF0moMJ1hK9YQwDTHKh6I7/uSckMetoRGb5UBZPC1z0jlw+n/XCgjeH7y1AQ==",
       "dev": true
     },
+    "async-limiter": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/async-limiter/-/async-limiter-1.0.0.tgz",
+      "integrity": "sha512-jp/uFnooOiO+L211eZOoSyzpOITMXx1rBITauYykG3BRYPu8h0UcxsPNB04RR5vo4Tyz3+ay17tR6JVf9qzYWg==",
+      "dev": true
+    },
     "async-settle": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/async-settle/-/async-settle-1.0.0.tgz",
@@ -810,6 +921,12 @@
       "integrity": "sha1-EsJe/kCkXjwyPrhnWgoM5XsiNx8=",
       "dev": true
     },
+    "browser-process-hrtime": {
+      "version": "0.1.3",
+      "resolved": "https://registry.npmjs.org/browser-process-hrtime/-/browser-process-hrtime-0.1.3.tgz",
+      "integrity": "sha512-bRFnI4NnjO6cnyLmOV/7PVoDEMJChlcfN0z4s1YMBY989/SvlfMI1lgCnkFUs53e9gQF+w7qu7XdllSTiSl8Aw==",
+      "dev": true
+    },
     "browserify-aes": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/browserify-aes/-/browserify-aes-1.2.0.tgz",
@@ -1444,6 +1561,33 @@
         "randomfill": "^1.0.3"
       }
     },
+    "css": {
+      "version": "2.2.4",
+      "resolved": "https://registry.npmjs.org/css/-/css-2.2.4.tgz",
+      "integrity": "sha512-oUnjmWpy0niI3x/mPL8dVEI1l7MnG3+HHyRPHf+YFSbK+svOhXpmSOcDURUh2aOCgl2grzrOPt1nHLuCVFULLw==",
+      "dev": true,
+      "requires": {
+        "inherits": "^2.0.3",
+        "source-map": "^0.6.1",
+        "source-map-resolve": "^0.5.2",
+        "urix": "^0.1.0"
+      }
+    },
+    "cssom": {
+      "version": "0.3.6",
+      "resolved": "https://registry.npmjs.org/cssom/-/cssom-0.3.6.tgz",
+      "integrity": "sha512-DtUeseGk9/GBW0hl0vVPpU22iHL6YB5BUX7ml1hB+GMpo0NX5G4voX3kdWiMSEguFtcW3Vh3djqNF4aIe6ne0A==",
+      "dev": true
+    },
+    "cssstyle": {
+      "version": "1.2.2",
+      "resolved": "https://registry.npmjs.org/cssstyle/-/cssstyle-1.2.2.tgz",
+      "integrity": "sha512-43wY3kl1CVQSvL7wUY1qXkxVGkStjpkDmVjiIKX8R97uhajy8Bybay78uOtqvh7Q5GK75dNPfW0geWjE6qQQow==",
+      "dev": true,
+      "requires": {
+        "cssom": "0.3.x"
+      }
+    },
     "currently-unhandled": {
       "version": "0.4.1",
       "resolved": "https://registry.npmjs.org/currently-unhandled/-/currently-unhandled-0.4.1.tgz",
@@ -1478,6 +1622,17 @@
         "assert-plus": "^1.0.0"
       }
     },
+    "data-urls": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/data-urls/-/data-urls-1.1.0.tgz",
+      "integrity": "sha512-YTWYI9se1P55u58gL5GkQHW4P6VJBJ5iBT+B5a7i2Tjadhv52paJG0qHX4A0OR6/t52odI64KP2YvFpkDOi3eQ==",
+      "dev": true,
+      "requires": {
+        "abab": "^2.0.0",
+        "whatwg-mimetype": "^2.2.0",
+        "whatwg-url": "^7.0.0"
+      }
+    },
     "date-now": {
       "version": "0.1.4",
       "resolved": "https://registry.npmjs.org/date-now/-/date-now-0.1.4.tgz",
@@ -1493,6 +1648,34 @@
         "ms": "2.0.0"
       }
     },
+    "debug-fabulous": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/debug-fabulous/-/debug-fabulous-1.1.0.tgz",
+      "integrity": "sha512-GZqvGIgKNlUnHUPQhepnUZFIMoi3dgZKQBzKDeL2g7oJF9SNAji/AAu36dusFUas0O+pae74lNeoIPHqXWDkLg==",
+      "dev": true,
+      "requires": {
+        "debug": "3.X",
+        "memoizee": "0.4.X",
+        "object-assign": "4.X"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "3.2.6",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-3.2.6.tgz",
+          "integrity": "sha512-mel+jf7nrtEl5Pn1Qx46zARXKDpBbvzezse7p7LqINmdoIk8PYP5SySaxEmYv6TZ0JyEKA1hsCId6DIhgITtWQ==",
+          "dev": true,
+          "requires": {
+            "ms": "^2.1.1"
+          }
+        },
+        "ms": {
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
+          "dev": true
+        }
+      }
+    },
     "decamelize": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/decamelize/-/decamelize-1.2.0.tgz",
@@ -1641,6 +1824,12 @@
       "integrity": "sha1-+hN8S9aY7fVc1c0CrFWfkaTEups=",
       "dev": true
     },
+    "detect-newline": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/detect-newline/-/detect-newline-2.1.0.tgz",
+      "integrity": "sha1-9B8cEL5LAOh7XxPaaAdZ8sW/0+I=",
+      "dev": true
+    },
     "diff": {
       "version": "3.5.0",
       "resolved": "https://registry.npmjs.org/diff/-/diff-3.5.0.tgz",
@@ -1673,6 +1862,15 @@
       "integrity": "sha512-jnjyiM6eRyZl2H+W8Q/zLMA481hzi0eszAaBUzIVnmYVDBbnLxVNnfu1HgEBvCbL+71FrxMl3E6lpKH7Ge3OXA==",
       "dev": true
     },
+    "domexception": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/domexception/-/domexception-1.0.1.tgz",
+      "integrity": "sha512-raigMkn7CJNNo6Ihro1fzG7wr3fHuYVytzquZKX5n0yizGsTcYgzdIUwj1X9pK0VvjeihV+XiclP+DjwbsSKug==",
+      "dev": true,
+      "requires": {
+        "webidl-conversions": "^4.0.2"
+      }
+    },
     "dotenv": {
       "version": "6.2.0",
       "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-6.2.0.tgz",
@@ -1961,6 +2159,27 @@
       "integrity": "sha1-G2HAViGQqN/2rjuyzwIAyhMLhtQ=",
       "dev": true
     },
+    "escodegen": {
+      "version": "1.11.1",
+      "resolved": "https://registry.npmjs.org/escodegen/-/escodegen-1.11.1.tgz",
+      "integrity": "sha512-JwiqFD9KdGVVpeuRa68yU3zZnBEOcPs0nKW7wZzXky8Z7tffdYUHbe11bPCV5jYlK6DVdKLWLm0f5I/QlL0Kmw==",
+      "dev": true,
+      "requires": {
+        "esprima": "^3.1.3",
+        "estraverse": "^4.2.0",
+        "esutils": "^2.0.2",
+        "optionator": "^0.8.1",
+        "source-map": "~0.6.1"
+      },
+      "dependencies": {
+        "esprima": {
+          "version": "3.1.3",
+          "resolved": "https://registry.npmjs.org/esprima/-/esprima-3.1.3.tgz",
+          "integrity": "sha1-/cpRzuYTOJXjyI1TXOSdv/YqRjM=",
+          "dev": true
+        }
+      }
+    },
     "eslint": {
       "version": "5.16.0",
       "resolved": "https://registry.npmjs.org/eslint/-/eslint-5.16.0.tgz",
@@ -2124,6 +2343,16 @@
       "integrity": "sha1-Cr9PHKpbyx96nYrMbepPqqBLrJs=",
       "dev": true
     },
+    "event-emitter": {
+      "version": "0.3.5",
+      "resolved": "https://registry.npmjs.org/event-emitter/-/event-emitter-0.3.5.tgz",
+      "integrity": "sha1-34xp7vFkeSPHFXuc6DhAYQsCzDk=",
+      "dev": true,
+      "requires": {
+        "d": "1",
+        "es5-ext": "~0.10.14"
+      }
+    },
     "events": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/events/-/events-3.0.0.tgz",
@@ -3490,6 +3719,33 @@
         }
       }
     },
+    "gulp-sourcemaps": {
+      "version": "2.6.5",
+      "resolved": "https://registry.npmjs.org/gulp-sourcemaps/-/gulp-sourcemaps-2.6.5.tgz",
+      "integrity": "sha512-SYLBRzPTew8T5Suh2U8jCSDKY+4NARua4aqjj8HOysBh2tSgT9u4jc1FYirAdPx1akUxxDeK++fqw6Jg0LkQRg==",
+      "dev": true,
+      "requires": {
+        "@gulp-sourcemaps/identity-map": "1.X",
+        "@gulp-sourcemaps/map-sources": "1.X",
+        "acorn": "5.X",
+        "convert-source-map": "1.X",
+        "css": "2.X",
+        "debug-fabulous": "1.X",
+        "detect-newline": "2.X",
+        "graceful-fs": "4.X",
+        "source-map": "~0.6.0",
+        "strip-bom-string": "1.X",
+        "through2": "2.X"
+      },
+      "dependencies": {
+        "acorn": {
+          "version": "5.7.3",
+          "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.7.3.tgz",
+          "integrity": "sha512-T/zvzYRfbVojPWahDsE5evJdHb3oJoQfFbsrKM7w5Zcs++Tr257tia3BmMP8XYVjp1S9RZXQMh7gao96BlqZOw==",
+          "dev": true
+        }
+      }
+    },
     "gulp-typescript": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/gulp-typescript/-/gulp-typescript-5.0.1.tgz",
@@ -3663,6 +3919,15 @@
       "integrity": "sha512-7T/BxH19zbcCTa8XkMlbK5lTo1WtgkFi3GvdWEyNuc4Vex7/9Dqbnpsf4JMydcfj9HCg4zUWFTL3Za6lapg5/w==",
       "dev": true
     },
+    "html-encoding-sniffer": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/html-encoding-sniffer/-/html-encoding-sniffer-1.0.2.tgz",
+      "integrity": "sha512-71lZziiDnsuabfdYiUeWdCVyKuqwWi23L8YeIgV9jSSZHCtb6wB1BKWooH7L3tn4/FuZJMVWyNaIDr4RGmaSYw==",
+      "dev": true,
+      "requires": {
+        "whatwg-encoding": "^1.0.1"
+      }
+    },
     "http-signature": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/http-signature/-/http-signature-1.2.0.tgz",
@@ -3866,6 +4131,12 @@
       "integrity": "sha512-wPVv/y/QQ/Uiirj/vh3oP+1Ww+AWehmi1g5fFWGPF6IpCBCDVrhgHRMvrLfdYcwDh3QJbGXDW4JAuzxElLSqKA==",
       "dev": true
     },
+    "ip-regex": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/ip-regex/-/ip-regex-2.1.0.tgz",
+      "integrity": "sha1-+ni/XS5pE8kRzp+BnuUUa7bYROk=",
+      "dev": true
+    },
     "is-absolute": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/is-absolute/-/is-absolute-1.0.0.tgz",
@@ -4142,6 +4413,59 @@
       "integrity": "sha1-peZUwuWi3rXyAdls77yoDA7y9RM=",
       "dev": true
     },
+    "jsdom": {
+      "version": "15.1.1",
+      "resolved": "https://registry.npmjs.org/jsdom/-/jsdom-15.1.1.tgz",
+      "integrity": "sha512-cQZRBB33arrDAeCrAEWn1U3SvrvC8XysBua9Oqg1yWrsY/gYcusloJC3RZJXuY5eehSCmws8f2YeliCqGSkrtQ==",
+      "dev": true,
+      "requires": {
+        "abab": "^2.0.0",
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@@ -4357,6 +4681,12 @@
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@@ -4376,6 +4706,15 @@
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@@ -4481,6 +4820,22 @@
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@@ -4819,6 +5174,12 @@
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@@ -4996,6 +5357,12 @@
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+      "resolved": "https://registry.npmjs.org/nwsapi/-/nwsapi-2.1.4.tgz",
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@@ -5499,6 +5866,12 @@
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+      "resolved": "https://registry.npmjs.org/pn/-/pn-1.1.0.tgz",
+      "integrity": "sha512-2qHaIQr2VLRFoxe2nASzsV6ef4yOOH+Fi9FBOVH6cqeSgUnoyySPZkxzLuzd+RYOQTRpROA0ztTMqxROKSb/nA==",
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+    },
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@@ -5947,6 +6320,26 @@
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+      "resolved": "https://registry.npmjs.org/request-promise-core/-/request-promise-core-1.1.2.tgz",
+      "integrity": "sha512-UHYyq1MO8GsefGEt7EprS8UrXsm1TxEvFUX1IMTuSLU2Rh7fTIdFtl8xD7JiEYiWU2dl+NYAjCTksTehQUxPag==",
+      "dev": true,
+      "requires": {
+        "lodash": "^4.17.11"
+      }
+    },
+    "request-promise-native": {
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/request-promise-native/-/request-promise-native-1.0.7.tgz",
+      "integrity": "sha512-rIMnbBdgNViL37nZ1b3L/VfPOpSi0TqVDQPAvO6U14lMzOLrt5nilxCQqtDKhZeDiW0/hkCXGoQjhgJd/tCh6w==",
+      "dev": true,
+      "requires": {
+        "request-promise-core": "1.1.2",
+        "stealthy-require": "^1.1.1",
+        "tough-cookie": "^2.3.3"
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@@ -6097,6 +6490,15 @@
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       "dev": true
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+    "saxes": {
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+      "resolved": "https://registry.npmjs.org/saxes/-/saxes-3.1.10.tgz",
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+      "dev": true,
+      "requires": {
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       "resolved": "https://registry.npmjs.org/schema-utils/-/schema-utils-1.0.0.tgz",
@@ -6520,6 +6922,12 @@
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+      "resolved": "https://registry.npmjs.org/stealthy-require/-/stealthy-require-1.1.1.tgz",
+      "integrity": "sha1-NbCYdbT/SfJqd35QmzCQoyJr8ks=",
+      "dev": true
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       "resolved": "https://registry.npmjs.org/stream-browserify/-/stream-browserify-2.0.2.tgz",
@@ -6603,6 +7011,12 @@
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+      "resolved": "https://registry.npmjs.org/strip-bom-string/-/strip-bom-string-1.0.0.tgz",
+      "integrity": "sha1-5SEekiQ2n7uB1jOi8ABE3IztrZI=",
+      "dev": true
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@@ -6716,6 +7130,12 @@
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+      "resolved": "https://registry.npmjs.org/symbol-tree/-/symbol-tree-3.2.4.tgz",
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+      "dev": true
+    },
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@@ -6917,6 +7337,16 @@
         "setimmediate": "^1.0.4"
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+    "timers-ext": {
+      "version": "0.1.7",
+      "resolved": "https://registry.npmjs.org/timers-ext/-/timers-ext-0.1.7.tgz",
+      "integrity": "sha512-b85NUNzTSdodShTIbky6ZF02e8STtVVfD+fu4aXXShEELpozH+bCpJLYMPZbsABN2wDH7fJpqIoXxJpzbf0NqQ==",
+      "dev": true,
+      "requires": {
+        "es5-ext": "~0.10.46",
+        "next-tick": "1"
+      }
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       "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.33.tgz",
@@ -7011,6 +7441,15 @@
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+      "resolved": "https://registry.npmjs.org/tr46/-/tr46-1.0.1.tgz",
+      "integrity": "sha1-qLE/1r/SSJUZZ0zN5VujaTtwbQk=",
+      "dev": true,
+      "requires": {
+        "punycode": "^2.1.0"
+      }
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     "trim-newlines": {
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       "resolved": "https://registry.npmjs.org/trim-newlines/-/trim-newlines-1.0.0.tgz",
@@ -7617,6 +8056,26 @@
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       "dev": true
     },
+    "w3c-hr-time": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/w3c-hr-time/-/w3c-hr-time-1.0.1.tgz",
+      "integrity": "sha1-gqwr/2PZUOqeMYmlimViX+3xkEU=",
+      "dev": true,
+      "requires": {
+        "browser-process-hrtime": "^0.1.2"
+      }
+    },
+    "w3c-xmlserializer": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/w3c-xmlserializer/-/w3c-xmlserializer-1.1.2.tgz",
+      "integrity": "sha512-p10l/ayESzrBMYWRID6xbuCKh2Fp77+sA0doRuGn4tTIMrrZVeqfpKjXHY+oDh3K4nLdPgNwMTVP6Vp4pvqbNg==",
+      "dev": true,
+      "requires": {
+        "domexception": "^1.0.1",
+        "webidl-conversions": "^4.0.2",
+        "xml-name-validator": "^3.0.0"
+      }
+    },
     "watchpack": {
       "version": "1.6.0",
       "resolved": "https://registry.npmjs.org/watchpack/-/watchpack-1.6.0.tgz",
@@ -7637,6 +8096,12 @@
         "defaults": "^1.0.3"
       }
     },
+    "webidl-conversions": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-4.0.2.tgz",
+      "integrity": "sha512-YQ+BmxuTgd6UXZW3+ICGfyqRyHXVlD5GtQr5+qjiNW7bF0cqrzX500HVXPBOvgXb5YnzDd+h0zqyv61KUD7+Sg==",
+      "dev": true
+    },
     "webpack": {
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       "resolved": "https://registry.npmjs.org/webpack/-/webpack-4.34.0.tgz",
@@ -7917,6 +8382,32 @@
         "source-map": "~0.6.1"
       }
     },
+    "whatwg-encoding": {
+      "version": "1.0.5",
+      "resolved": "https://registry.npmjs.org/whatwg-encoding/-/whatwg-encoding-1.0.5.tgz",
+      "integrity": "sha512-b5lim54JOPN9HtzvK9HFXvBma/rnfFeqsic0hSpjtDbVxR3dJKLc+KB4V6GgiGOvl7CY/KNh8rxSo9DKQrnUEw==",
+      "dev": true,
+      "requires": {
+        "iconv-lite": "0.4.24"
+      }
+    },
+    "whatwg-mimetype": {
+      "version": "2.3.0",
+      "resolved": "https://registry.npmjs.org/whatwg-mimetype/-/whatwg-mimetype-2.3.0.tgz",
+      "integrity": "sha512-M4yMwr6mAnQz76TbJm914+gPpB/nCwvZbJU28cUD6dR004SAxDLOOSUaB1JDRqLtaOV/vi0IC5lEAGFgrjGv/g==",
+      "dev": true
+    },
+    "whatwg-url": {
+      "version": "7.0.0",
+      "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-7.0.0.tgz",
+      "integrity": "sha512-37GeVSIJ3kn1JgKyjiYNmSLP1yzbpb29jdmwBSgkD9h40/hyrR/OifpVUndji3tmwGgD8qpw7iQu3RSbCrBpsQ==",
+      "dev": true,
+      "requires": {
+        "lodash.sortby": "^4.7.0",
+        "tr46": "^1.0.1",
+        "webidl-conversions": "^4.0.2"
+      }
+    },
     "which": {
       "version": "1.3.1",
       "resolved": "https://registry.npmjs.org/which/-/which-1.3.1.tgz",
@@ -8016,6 +8507,21 @@
         "mkdirp": "^0.5.1"
       }
     },
+    "ws": {
+      "version": "7.0.1",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-7.0.1.tgz",
+      "integrity": "sha512-ILHfMbuqLJvnSgYXLgy4kMntroJpe8hT41dOVWM8bxRuw6TK4mgMp9VJUNsZTEc5Bh+Mbs0DJT4M0N+wBG9l9A==",
+      "dev": true,
+      "requires": {
+        "async-limiter": "^1.0.0"
+      }
+    },
+    "xml-name-validator": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/xml-name-validator/-/xml-name-validator-3.0.0.tgz",
+      "integrity": "sha512-A5CUptxDsvxKJEU3yO6DuWBSJz/qizqzJKOMIfUJHETbBw/sFaDxgd6fxm1ewUaM0jZ444Fc5vC5ROYurg/4Pw==",
+      "dev": true
+    },
     "xml2js": {
       "version": "0.4.19",
       "resolved": "https://registry.npmjs.org/xml2js/-/xml2js-0.4.19.tgz",
@@ -8032,6 +8538,12 @@
       "integrity": "sha1-Ey7mPS7FVlxVfiD0wi35rKaGsQ0=",
       "dev": true
     },
+    "xmlchars": {
+      "version": "1.3.1",
+      "resolved": "https://registry.npmjs.org/xmlchars/-/xmlchars-1.3.1.tgz",
+      "integrity": "sha512-tGkGJkN8XqCod7OT+EvGYK5Z4SfDQGD30zAa58OcnAa0RRWgzUEK72tkXhsX1FZd+rgnhRxFtmO+ihkp8LHSkw==",
+      "dev": true
+    },
     "xtend": {
       "version": "4.0.1",
       "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.1.tgz",
diff --git a/package.json b/package.json
index 2b10ab7..8d1e7ac 100644
--- a/package.json
+++ b/package.json
@@ -30,6 +30,7 @@
     "eslint-plugin-prettier": "^3.1.0",
     "gulp": "^4.0.2",
     "gulp-cli": "^2.2.0",
+    "gulp-sourcemaps": "^2.6.5",
     "gulp-typescript": "^5.0.1",
     "prettier": "^1.18.2",
     "sqlite3": "^4.0.9",
diff --git a/tsconfig.json b/tsconfig.json
index 2303a2d..a343173 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -16,7 +16,9 @@
       {
         "name": "typescript-tslint-plugin"
       }
-    ]
+    ],
+    "rootDir": "src",
+    "outDir": "dist"
   },
   "include": ["src/**/*"]
 }