title: Image Manipulation library will not create a thumbnail
body: <p>I have created a library file that manages gallery functions, when a user uploads an image.</p>
  
  <p>This code will not create a thumbnail - it tries to resize the original image - am i missing something obvious?</p>
  
  <pre><code>private function _create_thumbnail($file_path)
  {
      $config['image_library']  = 'gd2';
      $config['source_image']   = $file_path;
      $config['create_thumb']   = 1;
      $config['maintain_ratio'] = 1;
      $config['width']          = 90;
      $config['height']         = 90;
  
      $this-&gt;CI-&gt;load-&gt;library('image_lib', $config); 
      $this-&gt;CI-&gt;image_lib-&gt;initialize($config);
  
      $result = $this-&gt;CI-&gt;image_lib-&gt;resize();
      print_r( $this-&gt;CI-&gt;image_lib-&gt;display_errors());
      print_r($config);
  
      // if(!$result) {
      //  // echo $this-&gt;CI-&gt;image_lib-&gt;display_errors(); 
      //  print_r($this-&gt;CI-&gt;image_lib-&gt;display_errors()); 
      // } 
  
      return $result;
  }
  </code></pre>