title: Integration fabricjs with requirejs
body: <p>I want to use <code>fabricjs</code> with require. I have other projects where i'm using <code>requirejs</code> so everything is configured right.
  <code>fabricjs</code> is build with require support. I'm not clear why in dist file i have generated <code>fabric.require.js</code> and <code>fabric.js</code> but i tested all and not work.</p>
  
  <p>Sample code (essential part):</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>define(['fabric','jquery'], function (fabric,$) { 
    function Graph(config) {
     
      var canvas = new fabric.Canvas('mycanvas');
      
      var circle = new fabric.Circle({
     radius: 20, fill: 'green', left: 100, top: 100
      });
      
    }
    
    return Graph;
  }); </code></pre>
  </div>
  </div>
  </p>
  
  <p>When i try to run this i got error: <code>fabric.Canvas</code> is not a function.
  What is strange, when comment line where <code>fabric.Canvas</code> is invoked, code run without error so it's like <code>fabric.Circle</code> call is ok.
  Where is the problem?</p>