Apply consistent code style with `black`

[cthoyt]

I wanted to make a contribution to TDC but it's very difficult to read the code because of a lack of consistent formatting and styling. There's a tool called black that can be used to standardize the code layout (and also work towards reducing diff). You can apply it with:

git clone https://github.com/mims-harvard/TDC.git
cd TDC
pip install black
black .

Warning
This will create a big diff (thousands of lines over 235 files), but it is worth it since it will better enable contributions.

Note that black is only a step towards writing understandable code. There are also a lot of things that could be improved in terms of documentation and software engineering practices. I could give a more detailed code review if you'd like.

[kexinhuang12345]

Hi Charles, thanks for the great suggestion! I will do the black code style right away (#188) and in the mean time, if you have any suggestions to improve the TDC doc/code, please let us know as well! thanks!