Import Debian changes 18.1-5
python-pip (18.1-5) unstable; urgency=medium * Team upload. * Refresh hands-off-system-packages.patch. * Add Properly_catch_requests_HTTPError_in_index.py.patch: this fixes 404 when using --extra-index-url due to the way we de-bundle python-requests from pip. Thanks to Fabio Natali <email@example.com> for the bug report, Clark Boylan for the patch, and all of the OpenStack infra team for their help and involving me for this fix (Closes: #837764).