Install manila tempest tests
Install manila tempest tests

Manila uses the new tempest plugin interface to add tempest tests.
So when running "testr list-tests" or "testr run", the tests need
to be installed.
This fixes:

ImportError: No module named manila_tempest_tests.plugin

SUSE-Cloud/openstack-quickstart,toabctl/openstack-quickstart,sjamgade/openstack-quickstart