Add tempest functional test coverage to OpenStack charms

A subset of tempest tests can be added via zaza to get better functional test coverage for the payload deployed by the charms. This should be something that can be added for all of the openstack charms, whether it's a single tempest test or many.

Example for cinder:

diff --git a/tests/tests.yaml b/tests/tests.yaml
index 50aff23..8aaf0d6 100644
--- a/tests/tests.yaml
+++ b/tests/tests.yaml
@@ -19,10 +19,21 @@ configure:
 - zaza.openstack.charm_tests.neutron.setup.basic_overcloud_network
 - zaza.openstack.charm_tests.nova.setup.create_flavors
 - zaza.openstack.charm_tests.nova.setup.manage_ssh_key
+- zaza.openstack.charm_tests.tempest.setup.add_cirros_alt_image
+- zaza.openstack.charm_tests.tempest.setup.add_tempest_flavors
+- zaza.openstack.charm_tests.tempest.setup.add_tempest_roles
+- zaza.openstack.charm_tests.tempest.setup.render_tempest_config_keystone_v3
 tests:
 - zaza.openstack.charm_tests.cinder.tests.CinderTests
 - zaza.openstack.charm_tests.cinder.tests.SecurityTests
 - zaza.openstack.charm_tests.policyd.tests.CinderTests
+- zaza.openstack.charm_tests.tempest.tests.TempestTest
 tests_options:
   policyd:
     service: cinder
+ tempest:
+ default:
+ regex:
+ - "cinder_tempest_plugin"
+ - "tempest.api.volume"
+ - "tempest.scenario.test_volume_*"

This assumes zaza-openstack-tests has the following in requirements.txt:

git+https://opendev.org/openstack/tempest.git#egg=tempest
git+https://opendev.org/openstack/cinder-tempest-plugin.git#egg=cinder-tempest-plugin