Bump omniauth-github from 1.1.2 to 1.2.2

Bumps [omniauth-github](https://github.com/intridea/omniauth-github) from 1.1.2 to 1.2.2.
- [Release notes](https://github.com/intridea/omniauth-github/releases/tag/v1.2.2)
- [Commits](omniauth/omniauth-github@v1.1.2...v1.2.2)

I'll automatically resolve any conflicts with this PR as long as you don't alter it yourself.

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Gemfile.lock

@@ -177,21 +177,19 @@ GEM
     net-http-pipeline (1.0.1)
     nokogiri (1.7.2)
       mini_portile2 (~> 2.1.0)
-    oauth2 (1.3.1)
-      faraday (>= 0.8, < 0.12)
+    oauth2 (1.4.0)
+      faraday (>= 0.8, < 0.13)
       jwt (~> 1.0)
       multi_json (~> 1.3)
       multi_xml (~> 0.5)
       rack (>= 1.2, < 3)
     omniauth (1.4.2)
       hashie (>= 1.2, < 4)
       rack (>= 1.0, < 3)
-    omniauth-github (1.1.2)
-      omniauth (~> 1.0)
-      omniauth-oauth2 (~> 1.1)
-    omniauth-oauth2 (1.2.0)
-      faraday (>= 0.8, < 0.10)
-      multi_json (~> 1.3)
+    omniauth-github (1.2.2)
+      omniauth (~> 1.4.0)
+      omniauth-oauth2 (>= 1.4.0, < 2.0)
+    omniauth-oauth2 (1.4.0)
       oauth2 (~> 1.0)
       omniauth (~> 1.2)
     orm_adapter (0.5.0)