It adds cats controller.

On branch master
Changes to be committed:
	new file:   app/assets/javascripts/cats.js.coffee
	new file:   app/assets/stylesheets/cats.css.scss
	new file:   app/controllers/cats_controller.rb
	new file:   app/helpers/cats_helper.rb
	new file:   app/views/cats/index.html.erb
	modified:   config/routes.rb
	new file:   test/controllers/cats_controller_test.rb
	new file:   test/helpers/cats_helper_test.rb