Flake8 Warnings

[rsdel2007]

I run the flake8 tests on the cloned repository and found that the code is filled with these warnings:
E501
E306
F841
E231
E301
E128
W291
W293
F401
E127
W391
F305
E203
E303
E741
E305
W605
E302
F401
E261
E225
E124
E114
E116

I will be happy to fix some of them.

Versions and main components

• PyMC3 Version:3.5
• Theano Version: 1.0.3
• Python Version: 3.6.5
• Operating system: ubuntu 16.04
• How did you install PyMC3: pip

[eigenfoo]

Hello @rsdel2007!

I like to have style-conformant code as much as anybody, and a simple autopep8 would probably fix all these warnings. However, the PyMC project has been here before: #3239 (comment).

The tldr is that, since refactoring code for style would touch many lines in the code base, a simple git blame would not come up with anything useful. By all means we should write pep8-comformant code going forward, but touching everything to conform to PEP8 is a bit extreme.

@aseyboldt unless you disagree, I think we should close this?