Extract railtie to its own file.

Author: lucasmazza

lib/rails-controller-testing.rb

@@ -1,8 +1,3 @@
 require 'rails/controller/testing'
+require 'rails/controller/testing/railtie' if defined?(Rails::Railtie)
 require 'rails/controller/testing/version'
-
-class Rails::Controller::Testing::Railtie < Rails::Railtie
-  initializer "rails_controller_testing" do
-    Rails::Controller::Testing.install
-  end
-end

lib/rails/controller/testing/railtie.rb

@@ -0,0 +1,5 @@
+class Rails::Controller::Testing::Railtie < Rails::Railtie
+  initializer "rails_controller_testing" do
+    Rails::Controller::Testing.install
+  end
+end