title: Ionic 3 post image using form-data
body: <p>I'm trying to post form data, consists of text and image file to PHP server.
  I use ionic native camera to get a picture from gallery:</p>
  
  <pre><code>const options: CameraOptions = {
      quality: 70,
      destinationType: this.camera.DestinationType.FILE_URI,
      sourceType: this.camera.PictureSourceType.PHOTOLIBRARY,
      saveToPhotoAlbum:false,
      targetWidth: 400,
      targetHeight: 400
  }
  
  this.camera.getPicture(options).then((imageData) =&gt; {
    this.myphoto = normalizeURL(imageData);
    this.myphoto2 = imageData;
  }, (err) =&gt; {
  
  });
  </code></pre>
  
  <p>And post it using form data:    </p>
  
  <pre><code>var headers = new Headers();
  headers.append('Content-Type', 'multipart/form-data;boundary=' + Math.random());
  headers.append('Accept', 'application/json');
  let options = new RequestOptions({
      headers: headers
  });
  let formData = new FormData();
  formData.append('judul', this.judul.value);
  formData.append('photo', this.myphoto, '123.jpg');
  this.http.post('http://localhost/upload.php', formData, options)
      .map(...)
      .subscribe(...);
  </code></pre>
  
  <p>But, I saw on PHP log, the form-data not sent by ionic.
  What's wrong here?</p>