title: Jquery UI Draggable clone disappearing
body: <p>I am trying to use the <code>jquery-ui draggable</code> to make some element draggable.
  I set the <code>helper</code> option to <code>clone</code>  the current element.<br>
  It's making the clone correctly but when I drop the clone disappears. It doesn't stay at the dragged place.</p>
  
  <p>See this for Demo <a href="https://jsfiddle.net/b76vbr0h/" rel="nofollow">Fiddle Link</a></p>
  
  <pre><code>$('#drag').draggable({
  helper: function (e, ui) {
      return $(this).clone();
  }
  });
  </code></pre>
  
  <p>What am I missing ?</p>