Enable more pep8 checks

Change-Id: Ib8509391d4c4521e18f0e980003c5e94c7ba2f54
Fix install_venv.py requirements file

I missed this in https://review.openstack.org/#/c/29876/
(but Gordon noticed)

Change-Id: Ie00cae414ae44bbd258910a2628174487c9756e3
Merge "Fix install_venv.py requirements file"