title: Materializecss - scrollFire plugin seems not to be working
body: <p>I don't have any idea why scrollfire plugin doesn't work
  I use official guide <a href="http://materializecss.com/scrollfire.html" rel="nofollow">http://materializecss.com/scrollfire.html</a></p>
  
  <p>javascript is the following:</p>
  
  <pre><code>        var options = [
  
  {selector: '.activator', offset: 500, callback: function() {
    Materialize.fadeInImage(".activator");
  } }
    ];
  
   Materialize.scrollFire(options);
  </code></pre>
  
  <p>Here's my plunker demo: <a href="http://embed.plnkr.co/aA66og3NhkhafSHLQC5R/" rel="nofollow">http://embed.plnkr.co/aA66og3NhkhafSHLQC5R/</a></p>
  
  <p>Do you have any ideas why it doesn't work?</p>