Add Python3 yoga unit tests
Add Python3 yoga unit tests

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

See also the PTI in governance [1].

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

Change-Id: Icfc46e4f80c8877a688d1c898d380a4c18a13c7c

openstack/python-heatclient