title: Facebook request not showing notifications
body: <p>Im using the following code to let users invite their friends in my webapp game:</p>
  
  <pre><code>FB.ui({
    method: 'apprequests',
    message: 'Let's play together!'
  }, function(response){
    console.log(response);
  });
  </code></pre>
  
  <p>But invited friends doesn't receive any notification, they only see the game request in the Gameroom.
  The app is set as game, and is already public and visible in the gameroom.</p>
  
  <p>What am I missing?</p>
  
  <p>I also tried to send a notification with the notification api. I get i "success" response, but no notification is shown to the user.</p>