Create a python virtual environment using conda, and then install the tensorflow:
$ conda create -n [environment-name] python=3.6
# it may ask for installing python-3.6 if you don't have it already. Type "y" to proceed...
$ activate [environment-name]
$ pip install tensorflow
From now on, you can activate the environment whenever you want to use tensorflow.
If you don't have the conda package manager, first download it from here: https://www.anaconda.com/distribution