add python 3.7 unit test job
This is a mechanically generated patch to add a unit test job running
under Python 3.7.
See ML discussion here [1] for context.
[1] http://lists.openstack.org/pipermail/openstack-dev/2018-October/135626.html
Change-Id: Id18fa521b9903d60f1439e8279ab8e2e044b8a19
Story: #2004073
Task: #27440
Corey Bryant
5 years ago