Use templates for cover and lower-constraints

Use openstack-tox-cover template, this runs the cover job
in the check queue only.

Use openstack-lower-constraints-jobs template.

Remove jobs that are part of the templates.

Change-Id: I65f03adfc05134bf5ddaa802b97b80d14a0b412d

.zuul.yaml

@@ -1,11 +1,13 @@
 - project:
     templates:
+      - check-requirements
+      - openstack-cover-jobs
+      - openstack-lower-constraints-jobs
       - openstack-python-jobs
       - openstack-python35-jobs
       - openstack-python36-jobs
-      - publish-openstack-docs-pti
-      - check-requirements
       - periodic-stable-jobs
+      - publish-openstack-docs-pti
       - release-notes-jobs-python3
     check:
       jobs:
@@ -13,20 +15,13 @@
         - murano-rally-task
         - murano-tempest-api
         - murano-tempest-cfapi
-        - openstack-tox-lower-constraints
-        - openstack-tox-cover:
-            voting: false
     gate:
       queue: murano
       jobs:
         - murano-tempest-api
-        - openstack-tox-lower-constraints
     experimental:
       jobs:
         - murano-functional
-    post:
-      jobs:
-        - openstack-tox-cover
 
 - job:
     name: murano-congress-devstack