Add Python3 wallaby unit tests
Add Python3 wallaby unit tests

This is an automatically generated patch to ensure unit testing
is in place for all the of the tested runtimes for wallaby.

See also the PTI in governance [1].

[1]: https://governance.openstack.org/tc/reference/project-testing-interface.html

Change-Id: I017723df2eca2e3aa00553f19628bfbd8aa93f41

openstack/oslo.db,openstack/oslo.db