Implements DeepMind's third nature paper, [Hybrid computing using a neural network with dynamic external memory](http://www.nature.com/nature/journal/v538/n7626/full/nature20101.html) by Graves et. al.
Based on the paper's appendix, I sketched the [computational graph](https://docs.google.com/drawings/d/1Fc9eOH1wPw0PbBHWkEH39jik7h7HT9BWAE8ZhSr4hJc/edit?usp=sharing)
I have a general framework and a couple Jupyter notebooks for debugging. This is not a finished project. It's still very much in the dev stage. I need to: