Code should be autoformated with autopep8

[ScottWeinstein]

Describe the problem. Formatting code by hand is tedious for developers and adds cost to review cycles.

Describe the solution you'd like gs-quant code should be autoformatted via a tool such as https://github.com/hhatto/autopep8

Describe alternatives you've considered None yet

Are you willing to contribute Yes

[femtotrader]

Black can also help.

It's currently used in pandas-datareader

You should have a look at .travis.yml