Add rubocop-rails gem

.hound.yml

@@ -1,6 +1,6 @@
 ruby:
   config_file: .rubocop.yml
-  version: 0.68.0
+  version: 0.72.0
 
 eslint:
   enabled: true

.rubocop.yml

@@ -1,4 +1,6 @@
-require: rubocop-performance
+require:
+  - rubocop-performance
+  - rubocop-rails
 
 AllCops:
   Exclude:

Gemfile

@@ -126,6 +126,7 @@ group :development, :test do
   gem 'rspec-rails', '>= 4.0.0.beta2'
   gem 'rubocop', '>= 0.59.0', require: false
   gem 'rubocop-performance'
+  gem 'rubocop-rails'
   gem 'timecop'
 end
 

Gemfile.lock

@@ -497,6 +497,9 @@ GEM
       unicode-display_width (>= 1.4.0, < 1.7)
     rubocop-performance (1.4.1)
       rubocop (>= 0.71.0)
+    rubocop-rails (2.3.2)
+      rack (>= 1.1)
+      rubocop (>= 0.72.0)
     ruby-graphviz (1.2.4)
     ruby-progressbar (1.10.1)
     ruby-vips (2.0.15)
@@ -677,6 +680,7 @@ DEPENDENCIES
   rspec-rails (>= 4.0.0.beta2)
   rubocop (>= 0.59.0)
   rubocop-performance
+  rubocop-rails
   ruby-graphviz (~> 1.2)
   rubyzip
   rufus-scheduler (~> 3.5)