title: Image does not uploaded in vue-codeigniter
body: <p>I build an app use vue and codeigniter rest server, I try to upload file by postman and it's work fine, but when I try from front-end, file is not uploaded, folder permission has been allowed, this is my vue code </p>
  
  <pre><code>data() {
     return {
        data: {
           photo: // base64 data
        }
     }
  }
  </code></pre>
  
  <p>on methods</p>
  
  <pre><code>addMember(){
     this.axios.post('member', this.data).then(res =&gt; {
        console.log(res)
     }).catch(err =&gt; {
        console.log(err)
     })
  }
  </code></pre>
  
  <p>on back end</p>
  
  <pre><code>$filename = round(microtime(true)).'.png';
  $config['file_name']            = $filename;
  $config['upload_path']          = './storage/';
  $config['allowed_types']        = '*';
  $config['max_size']             = 50000;
  $config['max_width']            = 50000;
  $config['max_height']           = 50000;
  
  $this-&gt;load-&gt;library('upload', $config);
  $this-&gt;upload-&gt;do_upload('photo');
  </code></pre>
  
  <p>thanks for your response</p>