title: tests and database_cleaner for multiple databases
body: <p>We have a Mailbox model which uses a secondary DB to which another mail app also connects. This is called using </p>
  
  <pre><code>establish_connection :mail_database
  </code></pre>
  
  <p>Now, I suppose I could attempt to wrap that in an <code>if</code> statement so it uses a different connection for the test environment, but I'm wondering how I could keep this database clean, preferably using database_cleaner which we already use for the 'regular' database.</p>
  
  <p>I hope someone can nudge me in the right direction.</p>