title: plot_model not working because "dot" with args
body: <p>When i'm trying to use plot_model it doesn'to work:</p>
  
  <pre><code>from keras.utils.vis_utils import plot_model
  plot_model(model, to_file='model_plot.png', show_shapes=True, show_layer_names=True)
  </code></pre>
  
  <p>and i get this message in the terminal:</p>
  
  <p>"dot" with args ['-Tps', 'C:\Users\CHETEM~1\AppData\Local\Temp\tmprst0j6pn'] returned code: 1</p>
  
  <p>stdout, stderr:
   b''
  b"'C:\Users\Chete' is not recognized as an internal or external command,\r\noperable program or batch file.\r\n"</p>
  
  <p>any one have any idea?</p>