Windows flake8 output is different than unixen

[msherry]

See #11 for the motivating report, but we should be able to handle output from Windows-run linters as well as OSX/Linux.

[sfavazza]

Hi I did some tests, and contrary to what you observed in the output I posted in #11, the output is the one from the error pipe and it's the same as the one of mypy or pylint. Actually in linux it perfectly works, only in Windows for some reason the flake8 output is not parsed by flycheck. I think I have to investigate directly the flycheck implementation...or probably just ensure that I have the last version of the *.el file.

Do you have any suggestion on how to step through the lisp file of flycheck when called?