tox: make sure flake8 is executed only against the revisione *.py files
tox: make sure flake8 is executed only against the revisione *.py files

Q-Leap-Networks/psutil,mrjefftang/psutil,jorik041/psutil,packages/psutil,qbit/psutil,packages/psutil,qbit/psutil,giampaolo/psutil,packages/psutil,jorik041/psutil,msarahan/psutil,Q-Leap-Networks/psutil,mrjefftang/psutil,msarahan/psutil,0-wiz-0/psutil,jamesblunt/psutil,jorik041/psutil,jamesblunt/psutil,cloudbase/psutil,jamesblunt/psutil,cloudbase/psutil,0-wiz-0/psutil,cloudbase/psutil,msarahan/psutil,qbit/psutil,giampaolo/psutil,mrjefftang/psutil