Update omniauth requirement from ~> 1.0 to >= 1, < 3

Updates the requirements on [omniauth](https://github.com/omniauth/omniauth) to permit the latest version.
- [Release notes](https://github.com/omniauth/omniauth/releases)
- [Commits](https://github.com/omniauth/omniauth/compare/v1.8.1...v2.1.0)

---
updated-dependencies:
- dependency-name: omniauth
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -3,35 +3,43 @@ PATH
   specs:
     omniauth-mastodon (0.9.3)
       i18n (~> 0.7)
-      omniauth (~> 1.0)
+      omniauth (>= 1, < 3)
       omniauth-oauth2 (~> 1.1)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    concurrent-ruby (1.0.5)
-    faraday (0.12.2)
-      multipart-post (>= 1.2, < 3)
-    hashie (3.5.7)
+    concurrent-ruby (1.1.10)
+    faraday (2.5.2)
+      faraday-net_http (>= 2.0, < 3.1)
+      ruby2_keywords (>= 0.0.4)
+    faraday-net_http (3.0.0)
+    hashie (5.0.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jwt (1.5.6)
-    multi_json (1.13.1)
+    jwt (2.5.0)
     multi_xml (0.6.0)
-    multipart-post (2.0.0)
-    oauth2 (1.4.0)
-      faraday (>= 0.8, < 0.13)
-      jwt (~> 1.0)
-      multi_json (~> 1.3)
+    oauth2 (2.0.7)
+      faraday (>= 0.17.3, < 3.0)
+      jwt (>= 1.0, < 3.0)
       multi_xml (~> 0.5)
       rack (>= 1.2, < 3)
-    omniauth (1.8.1)
-      hashie (>= 3.4.6, < 3.6.0)
-      rack (>= 1.6.2, < 3)
-    omniauth-oauth2 (1.5.0)
-      oauth2 (~> 1.1)
-      omniauth (~> 1.2)
-    rack (2.0.8)
+      rash_alt (>= 0.4, < 1)
+      version_gem (~> 1.1)
+    omniauth (2.1.0)
+      hashie (>= 3.4.6)
+      rack (>= 2.2.3)
+      rack-protection
+    omniauth-oauth2 (1.8.0)
+      oauth2 (>= 1.4, < 3)
+      omniauth (~> 2.0)
+    rack (2.2.4)
+    rack-protection (2.2.2)
+      rack
+    rash_alt (0.4.12)
+      hashie (>= 3.4)
+    ruby2_keywords (0.0.5)
+    version_gem (1.1.0)
 
 PLATFORMS
   ruby

omniauth-mastodon.gemspec

@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
   spec.require_paths = %w(lib)
   spec.version       = OmniAuth::Mastodon::Version
 
-  spec.add_dependency 'omniauth', '~> 1.0'
+  spec.add_dependency 'omniauth', '>= 1', '< 3'
   spec.add_dependency 'omniauth-oauth2', '~> 1.1'
   spec.add_dependency 'i18n', '~> 0.7'