In order to accept the requirements contract defined in
openstack/requirements, we need to sync with the master branch of that
project's global-requirements.txt and test-requirements.txt files.
Most of the changes are just version changes and nothing major. The
only major change is:
1) The twine dependency is removed, and therefore the pypi tox
environment was also removed.
Change-Id: Idbe9e73ddc5a34ac49aa6f6eff0779d46a75f583
Closes-Bug: #1533282
0ba8a35ade