title: AttributeError: module 'tensorflow' has no attribute 'name_scope' with Keras
body: <p>I am trying to run a script, but I struggle already at the imports.
  This import </p>
  
  <pre><code>from keras.preprocessing.image import save_img
  </code></pre>
  
  <p>raises the following error:</p>
  
  <pre><code>AttributeError: module 'tensorflow' has no attribute 'name_scope'.
  </code></pre>
  
  <p>I am using the following packages.</p>
  
  <pre><code>Keras                     2.2.2,                     
  Keras-Applications        1.0.4,                   
  Keras-Preprocessing       1.0.2,                   
  tensorflow                1.9.0,                     
  tensorflow-gpu            1.9.0                
  </code></pre>