title: Devise fields inside a password table
body: <p>Is that possible to setup Devise gem easily with every of its fields inside a passwords table, which is mapped with a Password model belonging to a User model (having just an <code>email</code> field)?</p>
  
  <p>In other words, here is a draw of my wanted model design:</p>
  
  <pre><code>         +-------+
           | User  |
           +-------+
           | email |
           +-------+
               ^ (have one)
               |
               | (belongs to)
  +------------------------+
  | Password               |
  +------------------------+
  | encrypted_password     |
  | reset_password_token   |
  | reset_password_sent_at |
  | sign_in_count          |
  | ...                    |
  +------------------------+
  </code></pre>
  
  <p>The Devise wiki is very complete, but there's not any info about this.</p>