title: Cannot import multi_gpu_model from keras.utils
body: <p>I have tensorflow-gpu 1.2.1 and keras on ubuntu 16.04. </p>
  
  <p>I am not able to perform:</p>
  
  <pre><code>from kears.utils import multi_gpu_model 
  </code></pre>
  
  <p>Has anyone had success with multi_gpu_model as described in their documentation's FAQ section?</p>
  
  <p>I have a 4 GPU machine with 4 GeForce GTX 1080 Ti cards and want to use all of them.</p>
  
  <p>Here's the error I get:</p>
  
  <pre><code>import keras.utils.multi_gpu_model
  
  ---------------------------------------------------------------------------
  ModuleNotFoundError                       Traceback (most recent call last)
  &lt;ipython-input-7-0174878249b1&gt; in &lt;module&gt;()
  ----&gt; 1 import keras.utils.multi_gpu_model
        2 
  
  ModuleNotFoundError: No module named 'keras.utils.multi_gpu_model'
  </code></pre>
  
  <p>I can import keras and keras.utils successfully.</p>