adding github rubocop

Gemfile

@@ -32,6 +32,7 @@ group :development, :mysql do
   gem 'travis-lint'
   gem 'better_errors'
   gem 'binding_of_caller'
+  gem 'rubocop-github'
 end
 
 gem 'simplecov', :require => false, :group => :test

Gemfile.lock

@@ -48,6 +48,7 @@ GEM
       ffi (~> 1.9.10)
       rspec-expectations (>= 2.99)
       thor (~> 0.19)
+    ast (2.3.0)
     backports (3.8.0)
     bcrypt (3.1.11)
     better_errors (2.3.0)
@@ -183,6 +184,9 @@ GEM
     notiffany (0.1.1)
       nenv (~> 0.1)
       shellany (~> 0.0)
+    parallel (1.12.0)
+    parser (2.4.0.0)
+      ast (~> 2.2)
     poltergeist (1.16.0)
       capybara (~> 2.1)
       cliver (~> 0.3.1)
@@ -190,6 +194,7 @@ GEM
     powder (0.3.2)
       thor (>= 0.11.5)
     power_assert (1.1.0)
+    powerpack (0.1.1)
     pry (0.11.1)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
@@ -225,6 +230,8 @@ GEM
       method_source
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
+    rainbow (2.2.2)
+      rake
     raindrops (0.19.0)
     rake (12.1.0)
     rb-fsevent (0.10.2)
@@ -255,7 +262,17 @@ GEM
       rspec-mocks (~> 3.6.0)
       rspec-support (~> 3.6.0)
     rspec-support (3.6.0)
+    rubocop (0.51.0)
+      parallel (~> 1.10)
+      parser (>= 2.3.3.1, < 3.0)
+      powerpack (~> 0.1)
+      rainbow (>= 2.2.2, < 3.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.0, >= 1.0.1)
+    rubocop-github (0.5.0)
+      rubocop (~> 0.49)
     ruby-prof (0.16.2)
+    ruby-progressbar (1.9.0)
     ruby_dep (1.5.0)
     sass (3.5.1)
       sass-listen (~> 4.0.0)
@@ -299,6 +316,7 @@ GEM
       thread_safe (~> 0.1)
     uglifier (3.2.0)
       execjs (>= 0.3.0, < 3)
+    unicode-display_width (1.3.0)
     unicorn (5.3.0)
       kgio (~> 2.6)
       raindrops (~> 0.7)
@@ -344,6 +362,7 @@ DEPENDENCIES
   rb-fsevent
   responders
   rspec-rails
+  rubocop-github
   ruby-prof
   sass-rails
   simplecov
@@ -359,4 +378,4 @@ RUBY VERSION
    ruby 2.4.2p198
 
 BUNDLED WITH
-   1.16.0.pre.2
+   1.16.0