title: How to change Keras/tensorflow version in Google colab?
body: <p>I'm using keras/tensorflow on google colaboratory and I need to go back to previous versions of them. </p>
  
  <p>The problem is when I run <code>!pip install q keras==1.2.2</code> , the kernel shows keras 1.2.2 installed but when I check it using <code>keras.__version_</code> it shows 2.1.6 . And same case is with tensorflow. </p>
  
  <p>How do I fix this?</p>