Add support for autopep8 aggressive option from config file

[andrewzigerelli]

This is so the user can specify aggressive option in pycodestyle config file.
e.g. in ~/.config/pycodestyle

[pycodestyle]
aggressive = 2

This seems to work. E.g.
No aggressive option leave this code as is:

if x == None:

With above pycodestyle and pull request, it makes this change:

if x is None:

Anyone who reads this: higher aggressive options than 0 should be used with care, as x is None does not always mean the same as x == None.

[palantirtech]

Thanks for your interest in palantir/python-language-server, @andrewzigerelli! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[goanpeca]

Thanks for working on this @andrewzigerelli

Could you add a small test for this ?

Using the x == None example should be enough in the test

[ccordoba12]

@andrewzigerelli, please also sign the CLA agreement so we can merge your PR (we can't do it without it).

[andrewzigerelli]

Does the current ci test pycodestlye config files? I'm not familiar with ci tests

[goanpeca]

Does the current ci test pycodestlye config files?
Yes

I'm not familiar with ci tests

Take a look at this file https://github.com/palantir/python-language-server/blob/develop/test/plugins/test_pycodestyle_lint.py

[andrewzigerelli]

@goanpeca
I wrote a small test and do

pytest test/plugins/test_pycodestyle_lint.py -s >2 log.out

This reads from my ~/.config/pycodestyle and is fine, but I don't see how this will pass ci validation.
Do I have to install circleci locally to see setup.cfg be preferred?

Further, test_pycodestyle_lint.py doesn't even seem to test the options defined in setup.cfg, unless I'm in the wrong file. I don't see any code which tests max-line-length = 120, or the ignore options..

[goanpeca]

Actually I think is fine to leave without a test for now :-)