Add support for removing features
Fix test description
Add route and controller action for destroy
Include markup and style feature header
Spec for removing feature through UI
Add ability to add feature in UI

Conflicts:
	lib/rollout_ui/engine/app/controllers/rollout_ui/features_controller.rb
	lib/rollout_ui/engine/config/routes.rb
	spec/requests/engine/engine_spec.rb
Bump version in Gemfile.lock