Explicitly enable tempest service
Explicitly enable tempest service

Add tempest as enabled_service explicitly, as the job disabled those in
ENABLED_SERVICE and this was making the tempest jobs not being able to
run.

Change-Id: I469887ce84263d4ee9269949bc1270b09cbea4fd
Signed-off-by: Daniel Mellado <f979c458027b400c5cb19668e84705b4a77965c2@redhat.com>

openstack-infra/project-config,openstack-infra/project-config