fix: .snyk, package.json & package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with a Snyk patch:
- https://snyk.io/vuln/SNYK-JS-LODASH-450202

.snyk

@@ -0,0 +1,10 @@
+# Snyk (https://snyk.io) policy file, patches or ignores known vulnerabilities.
+version: v1.13.5
+ignore: {}
+# patches apply the minimum changes required to fix a vulnerability
+patch:
+  SNYK-JS-LODASH-450202:
+    - node-sass > sass-graph > lodash:
+        patched: '2019-07-04T03:50:14.706Z'
+    - node-sass > gaze > globule > lodash:
+        patched: '2019-07-04T03:50:14.706Z'

package.json

@@ -27,7 +27,8 @@
     "node-sass": "^4.11.0",
     "original-fs": "^1.0.0",
     "semver": "^5.6.0",
-    "tar-fs": "^2.0.0"
+    "tar-fs": "^2.0.0",
+    "snyk": "^1.189.0"
   },
   "devDependencies": {
     "@babel/core": "^7.3.4",
@@ -100,6 +101,9 @@
     "release": "npm run lint && npm run build_release && gulp release && npm run package_release",
     "release_test": "npm run build_release && gulp release",
     "update_release": "npm run build_release && gulp release",
-    "inject": "node scripts/inject.js"
-  }
+    "inject": "node scripts/inject.js",
+    "snyk-protect": "snyk protect",
+    "prepare": "npm run snyk-protect"
+  },
+  "snyk": true
 }