title: Firebase "set" completion callback is not firing
body: <p>I was playing around with Firebase (free plan) and ran into an issue with the completion callback for <code>set</code> not being called when the data being set exceeded a certain number of keys. The limit varies depending on how deeply nested your data is but for a 1 deep object, that limit seems to be 1453 keys. Above 1453 and the completion callback never fires.</p>
  
  <pre><code>var data = {};
  
  // Change 1453 to 1454 and the completion callback never fires
  for (var i = 0; i &lt; 1453; i++) {
      data[i] = true;
  }
  
  rootRef.set(data, function (err) {
      console.log(err);
  });
  </code></pre>
  
  <p>Has anyone else encountered this issue or has a guess as to why it is happening?</p>
  
  <p>EDIT: I am doing this in node</p>