title: devise: adding notice after sign up (with confirmable)
body: <p>I added :confirmable to my Rails app subsequently. The problem is that when I sign up after adding :confirmable I don't get a notice displayed after the sign up for with telling me what happened, for instance:</p>
  
  <pre><code>You will receive an email with instructions about how to confirm your account in a few minutes.
  </code></pre>
  
  <p>Why doesn't notice appear and how can I add that notice after adding :confirmable?</p>
  
  <p>Thanks for help</p>