title: Guzzle ~6.0 multipart and form_params
body: <p>I am trying to upload file and send post parameters at the same time like this:</p>
  
  <pre><code>$response = $client-&gt;post('http://example.com/api', [
      'form_params' =&gt; [
          'name' =&gt; 'Example name',
      ],
      'multipart' =&gt; [
          [
              'name'     =&gt; 'image',
              'contents' =&gt; fopen('/path/to/image', 'r')
          ]
      ]
  ]);
  </code></pre>
  
  <p>However my form_params fields are ignored and only the multipart fields are present in my post body. Can I send both at all with guzzle 6.0 ?</p>