Cleanup ruby code via rubocop

This commit will add code cleanup as corrected
and alerted by rubocop. It also adds rules to
execute rubocop on Travis.

.sync.yml

@@ -3,3 +3,6 @@ appveyor.yml:
   delete: true
 spec/spec_helper.rb:
   allow_deprecations: true
+extras:
+- rvm: 2.1.9
+  script: bundle exec rake rubocop