title: angular file upload converting data/payload into string
body: <p>I have been using ng-file-upload to upload files to server. Recently I saw that it is converting payload/data that I am adding to it apart from file from any data type to string only. For example if I am sending integer or boolean field, it is converting it into string.
  I am using django at backend, so when I print type of request data it is showing unicode and in model I have defined NullBooleanField. Because of this everytime it takes it True and save it in database as True. Below is the little snippet of what I am doing.</p>
  
  <pre><code>var _data = {'name': 'xxx',' good':false};
  
  $scope.upload = $upload.upload({
   url: URL,
   method: 'PUT',
   file: data_file,
   data: _data,}).progress(function(evt){
  });
  </code></pre>
  
  <p>each time when I print the type of this at backend</p>
  
  <pre><code>type(print (request.DATA['good'])))
  </code></pre>
  
  <p>it return</p>
  
  <pre><code>&lt;type 'unicode'&gt;
  </code></pre>
  
  <p>Am i missing something here or something is actually wrong?</p>