Experimental PR for moving to Python 3 and Tensorflow 2

[gvol]

I wanted to use this code for a little experiment. Unfortunately, my time for the experiment ran out before I know that I got everything working on a modern Mac. I was able to generate some data (I only generated 100 examples) and train a model on those examples. I wanted to make sure everything worked before spending a lot of time training the model.

Anyway, the branch is super messy, but I would be willing to spend some time cleaning it up (and doing some more testing) if you were interested in merging it.