Tensorflow in the ci

Tensorflow 1.0 was released a week ago.

Now everything is available on pypi via wheels for linux and macosx (py27, py33, py34,py35,py36 - https://pypi.python.org/pypi/tensorflow/1.0.0) and we can nicely install it via pip.

pip install tensorflow-gpu

Would be nice to have it in the ci, because I just port bob.learn.tensorflow.

Shall I add this instruction the from-scratch.sh script?

Thanks