title: Active Admin - Same model for users and admins
body: <p>I'm looking to have Active Admin do the backend for a site. I don't really want to have separate models for Users and AdminUsers though.</p>
  
  <p>Can I have only admin users login to Active Admin if they have an is_admin flag in the Users model? If the users isn't an admin they should only be able to login to a simple control panel on the front of the site.</p>