Add rubocop

.travis.yml

@@ -8,3 +8,6 @@ rvm:
   - 2.3.0
 before_install:
   - rvm @global do gem install bundler
+script:
+  - bundle exec rspec
+  - bundle exec rubocop

Gemfile

@@ -15,6 +15,7 @@ group :development, :test do
   gem 'rspec', :require => false
   gem 'guard-rspec', :require => false
   gem 'terminal-notifier-guard', :require => false
+  gem 'rubocop', :require => false unless RUBY_VERSION =~ /^1.8/
 
   platforms :mri do
     gem 'pry', :require => false