title: Adding required email field to django when creating users with admin
body: <p>When creating/adding a user with Django admin; how can this be customized?</p>
  <p>For example, currently, the username and password are prompted for. However, I'd like to customize this to also have other required fields, such as 'email'?</p>
  <p>The Django tutorial isn't clear on admin user auth customization?</p>