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: Ie3e8d7b8a85251682c1a55dcfa610c232f067c8b

openstack/tooz,openstack/tooz