Bump omniauth and omniauth-github

Bumps [omniauth](https://github.com/omniauth/omniauth) and [omniauth-github](https://github.com/intridea/omniauth-github). These dependencies needed to be updated together.

Updates `omniauth` from 1.9.1 to 2.0.4
- [Release notes](https://github.com/omniauth/omniauth/releases)
- [Commits](omniauth/omniauth@v1.9.1...v2.0.4)

Updates `omniauth-github` from 1.4.0 to 2.0.0
- [Release notes](https://github.com/intridea/omniauth-github/releases)
- [Commits](omniauth/omniauth-github@v1.4.0...v2.0.0)

---
updated-dependencies:
- dependency-name: omniauth
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: omniauth-github
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile

@@ -30,9 +30,9 @@ gem 'jquery-rails'
 gem 'mocha', '~> 1.12'
 gem 'mimemagic', '~> 0.3.10'
 gem 'mustermann' , '1.1.1'
-gem 'omniauth', '~> 1.9'
+gem 'omniauth', '~> 2.0'
 gem 'omniauth-facebook', '~> 8.0'
-gem 'omniauth-github', '~> 1.4'
+gem 'omniauth-github', '~> 2.0'
 gem 'omniauth-google-oauth2'
 gem 'omniauth-twitter'
 gem "paperclip", "~> 6.1.0"

Gemfile.lock

@@ -319,31 +319,32 @@ GEM
     nokogumbo (2.0.4)
       nokogiri (~> 1.8, >= 1.8.4)
     oauth (0.5.6)
-    oauth2 (1.4.4)
+    oauth2 (1.4.7)
       faraday (>= 0.8, < 2.0)
       jwt (>= 1.0, < 3.0)
       multi_json (~> 1.3)
       multi_xml (~> 0.5)
       rack (>= 1.2, < 3)
-    omniauth (1.9.1)
+    omniauth (2.0.4)
       hashie (>= 3.4.6)
       rack (>= 1.6.2, < 3)
+      rack-protection
     omniauth-facebook (8.0.0)
       omniauth-oauth2 (~> 1.2)
-    omniauth-github (1.4.0)
-      omniauth (~> 1.5)
-      omniauth-oauth2 (>= 1.4.0, < 2.0)
+    omniauth-github (2.0.0)
+      omniauth (~> 2.0)
+      omniauth-oauth2 (~> 1.7.1)
     omniauth-google-oauth2 (0.8.1)
       jwt (>= 2.0)
       oauth2 (~> 1.1)
       omniauth (>= 1.1.1)
       omniauth-oauth2 (>= 1.6)
-    omniauth-oauth (1.1.0)
+    omniauth-oauth (1.2.0)
       oauth
-      omniauth (~> 1.0)
-    omniauth-oauth2 (1.7.0)
+      omniauth (>= 1.0, < 3)
+    omniauth-oauth2 (1.7.1)
       oauth2 (~> 1.4)
-      omniauth (~> 1.9)
+      omniauth (>= 1.9, < 3)
     omniauth-twitter (1.4.0)
       omniauth-oauth (~> 1.1)
       rack
@@ -649,9 +650,9 @@ DEPENDENCIES
   mustermann (= 1.1.1)
   mysql2 (>= 0.4.4)
   nifty-generators
-  omniauth (~> 1.9)
+  omniauth (~> 2.0)
   omniauth-facebook (~> 8.0)
-  omniauth-github (~> 1.4)
+  omniauth-github (~> 2.0)
   omniauth-google-oauth2
   omniauth-twitter
   openssl (~> 2.2.0)