title: How to stop (in order to reverse) a fabricjs animation
body: <p>I want to create a mouse rollover effect, like we used to see in flash websites - when the mouse rolls over an element it begins to animate, but if in the middle of the anim the mouse rolls out the animation would stop and run back.</p>
  
  <p>I would like to achieve the same effect with fabric, but I can seem to find a way to stop the animation. For example:</p>
  
  <pre><code>rect.animate('top', '200', {
      duration: 1000,
      onChange: canvas.renderAll.bind(canvas),
      onComplete: function() {
        //callback code goes here
      }
    });
  </code></pre>
  
  <p>This will animate until the <code>top</code> value of the <code>rect</code> will become <code>200</code>. Is there a way to stop animation before that?</p>