Janitor for straightening code style using flake8

@miketaylr Not mandatory to import. 
Your choice. I was trying to see if we could be consistent in the coding style of the project. There were different ways of doing things here and there. A lot is about docstrings and modules import. You can try first on your master branch with flake8.  

→ flake8 .
./webcompat/__init__.py:26:1: F401 'webcompat' imported but unused
./webcompat/api/endpoints.py:201:80: E501 line too long (81 > 79 characters)
./webcompat/api/endpoints.py:234:80: E501 line too long (81 > 79 characters)

There are 3 remaining defaults, but which are not necessary easy or necessary to fix.

The one I have struggles with is webcompat in __init__.py