Added a selector for users role in admin cp

app/models/user.rb

@@ -15,7 +15,7 @@ class User < ActiveRecord::Base
   validates :username, :presence => true, :uniqueness => true
 
   # Setup accessible (or protected) attributes for your model
-  attr_accessible :username, :email, :password, :password_confirmation, :remember_me, :is_admin
+  attr_accessible :username, :email, :password, :password_confirmation, :remember_me, :role_id
   
   has_many :topics, :dependent => :destroy
   has_many :posts, :dependent => :destroy