Introduct rubocop with GitHub config

.rubocop.yml

@@ -0,0 +1,10 @@
+inherit_gem:
+  rubocop-github:
+    - config/default.yml
+    - config/rails.yml
+
+AllCops:
+  TargetRubyVersion: 2.4
+
+Performance:
+  enabled: true

Gemfile

@@ -1,29 +1,31 @@
-source 'https://rubygems.org'
+# frozen_string_literal: true
+
+source "https://rubygems.org"
 ruby "2.4.2"
 
-gem 'rails', '4.2.10'
-
-gem 'asciidoctor', '>=1.5.4'
-gem 'faraday'
-gem 'faraday_middleware'
-gem 'octokit'
-gem 'puma'
-gem 'tilt'
-gem 'tire'
-gem 'iso8601'
-
-gem 'json'
-gem 'yajl-ruby'
-gem 'netrc'
-gem 'launchy'
-gem 'diff-lcs'
-gem 'redcarpet'
-gem 'nokogiri'
+gem "rails", "4.2.10"
+
+gem "asciidoctor", ">=1.5.4"
+gem "faraday"
+gem "faraday_middleware"
+gem "iso8601"
+gem "octokit"
+gem "puma"
+gem "tilt"
+gem "tire"
+
+gem "diff-lcs"
+gem "json"
+gem "launchy"
+gem "netrc"
+gem "nokogiri"
+gem "redcarpet"
+gem "yajl-ruby"
 
 # Assets
-gem 'compass-rails'
-gem 'sass-rails'
-gem 'uglifier', '3.2.0'
+gem "compass-rails"
+gem "sass-rails"
+gem "uglifier", "3.2.0"
 
 group :development do
   gem "awesome_print"
@@ -33,26 +35,27 @@ group :development do
 end
 
 group :development, :test do
-  gem 'dotenv-rails'
+  gem "bullet"
+  gem "dotenv-rails"
+  gem "pry-byebug"
+  gem "rubocop-github"
+  gem "ruby-prof"
   gem "sqlite3"
-  gem 'pry-byebug'
-  gem 'ruby-prof'
-  gem 'bullet'
 end
 
 group :test do
-  gem 'database_cleaner'
-  gem 'fabrication'
-  gem 'rspec-rails'
-  gem 'shoulda-matchers'
-  gem 'webmock'
-  gem 'vcr'
-  gem 'rails-perftest'
+  gem "database_cleaner"
+  gem "fabrication"
+  gem "rails-perftest"
+  gem "rspec-rails"
+  gem "shoulda-matchers"
+  gem "vcr"
+  gem "webmock"
 end
 
 group :production do
-  gem 'pg', '0.21.0'
-  gem 'rack-timeout'
-  gem 'rails_12factor'
-  gem 'redis-rails'
+  gem "pg", "0.21.0"
+  gem "rack-timeout"
+  gem "rails_12factor"
+  gem "redis-rails"
 end

Gemfile.lock

@@ -40,6 +40,7 @@ GEM
     ansi (1.5.0)
     arel (6.0.4)
     asciidoctor (1.5.6.1)
+    ast (2.4.0)
     awesome_print (1.8.0)
     better_errors (2.4.0)
       coderay (>= 1.0.0)
@@ -103,6 +104,7 @@ GEM
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
     iso8601 (0.10.1)
+    jaro_winkler (1.5.1)
     json (2.1.0)
     launchy (2.4.3)
       addressable (~> 2.3)
@@ -123,7 +125,11 @@ GEM
       mini_portile2 (~> 2.3.0)
     octokit (4.8.0)
       sawyer (~> 0.8.0, >= 0.5.3)
+    parallel (1.12.1)
+    parser (2.5.1.2)
+      ast (~> 2.4.0)
     pg (0.21.0)
+    powerpack (0.1.2)
     pry (0.11.3)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
@@ -166,6 +172,7 @@ GEM
       activesupport (= 4.2.10)
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
+    rainbow (3.0.0)
     rake (12.3.1)
     rb-fsevent (0.10.3)
     rb-inotify (0.9.10)
@@ -209,7 +216,18 @@ GEM
       rspec-mocks (~> 3.7.0)
       rspec-support (~> 3.7.0)
     rspec-support (3.7.1)
+    rubocop (0.60.0)
+      jaro_winkler (~> 1.5.1)
+      parallel (~> 1.10)
+      parser (>= 2.5, != 2.5.1.1)
+      powerpack (~> 0.1)
+      rainbow (>= 2.2.2, < 4.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.4.0)
+    rubocop-github (0.12.0)
+      rubocop (~> 0.59)
     ruby-prof (0.17.0)
+    ruby-progressbar (1.10.0)
     safe_yaml (1.0.4)
     sass (3.4.25)
     sass-rails (5.0.7)
@@ -249,6 +267,7 @@ GEM
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.5)
+    unicode-display_width (1.4.0)
     uniform_notifier (1.11.0)
     vcr (4.0.0)
     webmock (3.3.0)
@@ -290,6 +309,7 @@ DEPENDENCIES
   redcarpet
   redis-rails
   rspec-rails
+  rubocop-github
   ruby-prof
   sass-rails
   shoulda-matchers
@@ -305,4 +325,4 @@ RUBY VERSION
    ruby 2.4.2p198
 
 BUNDLED WITH
-   1.16.1
+   1.16.3