Update rails to 4.0:

* Add protected_attributes gem dependency;
* Remove deprecated usages of AR .find method;

config/environment.rb

@@ -1,5 +1,5 @@
-# Load the rails application
+# Load the Rails application.
 require File.expand_path('../application', __FILE__)
 
-# Initialize the rails application
+# Initialize the Rails application.
 Scube::Application.initialize!