How to change Keras/tensorflow version in Google colab?
In the latest colab, when you upgrade or downgrade a module, in the output cell you will automatically see the statement:
"WARNING: The following packages were previously imported in this runtime:
  [scipy]
You must restart the runtime in order to use newly installed versions.
" asking you to restart the runtime along with a button for it.
I'm using keras/tensorflow on google colaboratory and I need to go back to previous versions of them. 
The problem is when I run !pip install q keras==1.2.2 , the kernel shows keras 1.2.2 installed but when I check it using keras.__version_ it shows 2.1.6 . And same case is with tensorflow. 
How do I fix this?