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: I9607ff70e24f1fee298e1685c4cc7fbf46800d18
Story: #2004073
Task: #27417