Update tox.ini pep8
Update tox.ini pep8

Change-Id: I74ca119a55fd3949951863e8cf28ece5df89d927

stackforge/networking-plumgrid,openstack/networking-plumgrid,msagheer/networking-plumgrid,msagheer/networking-plumgrid,stackforge/networking-plumgrid,openstack/networking-plumgrid