Add Rubocop to CI (#356)

* Add Rubocop to CI

Make Travis run Rubocop before running the RSpec suite so we catch any style violations.

This resolves https://github.com/DEFRA/waste-carriers-renewals/issues/176

* Install Rubocop as dependency

.travis.yml

@@ -47,6 +47,10 @@ before_script:
   - if [ "$TRAVIS_PULL_REQUEST" == "false" ]; then curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter; fi
   - if [ "$TRAVIS_PULL_REQUEST" == "false" ]; then chmod +x ./cc-test-reporter; fi
   - if [ "$TRAVIS_PULL_REQUEST" == "false" ]; then ./cc-test-reporter before-build; fi
+  # Run rubocop. It's installed as a dependency (hence no install step) as this
+  # allows projects to control the version they are using (rather than getting)
+  # surprise build failures.
+  - bundle exec rubocop
 script:
   - bundle exec rspec
 after_script:

Gemfile

@@ -39,6 +39,8 @@ group :development, :test do
   gem "byebug"
   gem "dotenv-rails"
   gem "rspec-rails", "~> 3.6"
+  # Rubocop to ensure consistency in how the code is written
+  gem "rubocop"
 end
 
 group :development do

Gemfile.lock

@@ -62,6 +62,7 @@ GEM
       airbrake-ruby (~> 1.8)
     airbrake-ruby (1.8.0)
     arel (6.0.4)
+    ast (2.4.0)
     bcrypt (3.1.12)
     binding_of_caller (0.8.0)
       debug_inspector (>= 0.0.1)
@@ -130,6 +131,7 @@ GEM
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
     i18n_data (0.8.0)
+    jaro_winkler (1.5.2)
     jbuilder (2.8.0)
       activesupport (>= 4.2.0)
       multi_json (>= 1.2)
@@ -165,7 +167,11 @@ GEM
       sawyer (~> 0.8.0, >= 0.5.3)
     origin (2.3.1)
     orm_adapter (0.5.0)
+    parallel (1.12.1)
+    parser (2.5.3.0)
+      ast (~> 2.4.0)
     phonelib (0.6.28)
+    powerpack (0.1.2)
     public_suffix (3.0.3)
     rack (1.6.11)
     rack-test (0.6.3)
@@ -229,6 +235,15 @@ GEM
       rspec-mocks (~> 3.8.0)
       rspec-support (~> 3.8.0)
     rspec-support (3.8.0)
+    rubocop (0.62.0)
+      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)
+    ruby-progressbar (1.10.0)
     safe_yaml (1.0.4)
     sass (3.7.2)
       sass-listen (~> 4.0.0)
@@ -267,6 +282,7 @@ GEM
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.5)
+    unicode-display_width (1.4.1)
     unicode_utils (1.4.0)
     useragent (0.16.10)
     validates_email_format_of (1.6.3)
@@ -305,6 +321,7 @@ DEPENDENCIES
   rails-html-sanitizer (>= 1.0.4)
   rails_12factor
   rspec-rails (~> 3.6)
+  rubocop
   secure_headers (~> 5.0)
   simplecov
   spring