Updated to work with Python3

[tfboyd]

Changed to Python3 -() added to print statements

• _pickle used instead of cPickle

I ran a 1000 step run and the results were the same.

[tfboyd]

I doubt you want this and the change is trivial. I was messing around and thought I would open the pull request for fun. Thank you for the nice documentation. I found your model on reddit and wanted to give it a try locally.

[philipperemy]

LGTM