user authentication and tests
user authentication, feature tests, integration tests, sign in sign out
Merge branch 'master' into user_login

Conflicts:
	app/controllers/users_controller.rb
	app/views/users/show.html.erb
	config/routes.rb
	spec/controllers/users_controller_spec.rb
	spec/factories.rb
fix tests with stub signed_in true
Merge branch 'master' into article_caching

Conflicts:
	db/schema.rb
	spec/controllers/channels_controller_spec.rb