Fail the build on any RuboCop offense

.rubocop.yml

@@ -5,6 +5,7 @@ AllCops:
   Exclude:
     - 'bin/*'
     - 'db/schema.rb'
+    - 'db/seeds.rb'
 
 # Avoid long parameter lists
 ParameterLists:

.travis.yml

@@ -1,7 +1,9 @@
 ---
 before_install: gem update bundler
 before_script: bundle exec rake db:create db:schema:load
-after_script: bundle exec rubocop -R
+script:
+  - bundle exec rake
+  - bundle exec rubocop --rails --fail-level=refactor
 bundler_args: --without assets:development:production
 language: ruby
 rvm: