Add Python3 xena unit tests
Add Python3 xena unit tests

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

See also the PTI in governance [1].

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

Change-Id: I33b91ef17a3e51c17dbc609bf4b86eb4e443093f

openstack/vitrage-dashboard,openstack/vitrage-dashboard,openstack/vitrage-dashboard,openstack/vitrage-dashboard