Gemfile in flipper-0.12.2 vs Gemfile in flipper-0.13.0.beta1

@@ -22,9 +22,10 @@
 # for active support tests in test/ and only needed for ruby 2.2.x
 gem 'test-unit', '~> 3.0'
 
 group(:guard) do
   gem 'guard', '~> 2.12.5'
+  gem 'guard-rubocop', '~> 1.3.0'
   gem 'guard-rspec', '~> 4.5.0'
   gem 'guard-bundler', '~> 2.1.0'
   gem 'guard-coffeescript', '~> 2.0.1'
   gem 'guard-sass', '~> 1.6.0'
   gem 'rb-fsevent', '~> 0.9.4'