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.

Also, remove openstack-tox-docs job variant, the current template
handles this just fine with doc/requirements.txt, no need for this.

Change-Id: I04610329aee57e7bf25446318ec694d0e86d3889

.zuul.yaml

@@ -1,24 +1,18 @@
 - project:
     templates:
       - check-requirements
-      - periodic-stable-jobs-neutron
+      - openstack-cover-jobs-neutron
+      - openstack-lower-constraints-jobs-neutron
       - openstack-python-jobs-neutron
       - openstack-python35-jobs-neutron
       - openstack-python36-jobs-neutron
-      - release-notes-jobs-python3
+      - periodic-stable-jobs-neutron
       - publish-openstack-docs-pti
+      - release-notes-jobs-python3
     check:
       jobs:
         - neutron-fwaas-networking-midonet-cross-py35:
             voting: false
-
-        - openstack-tox-lower-constraints:
-            required-projects:
-              - openstack/neutron
-
-        - openstack-tox-docs:
-            required-projects:
-              - openstack/neutron
         - legacy-neutron-fwaas-v2-dsvm-tempest
         - legacy-neutron-fwaas-v1-dsvm-tempest
         - legacy-neutron-fwaas-dsvm-functional
@@ -33,22 +27,13 @@
             voting: false
     gate:
       jobs:
-        - openstack-tox-lower-constraints:
-            required-projects:
-              - openstack/neutron
-
-        - openstack-tox-docs:
-            required-projects:
-              - openstack/neutron
         - legacy-neutron-fwaas-v2-dsvm-tempest
         - legacy-neutron-fwaas-v1-dsvm-tempest
         - legacy-neutron-fwaas-dsvm-functional
     experimental:
       jobs:
         - legacy-neutron-fwaas-dsvm-fullstack
-    post:
-      jobs:
-        - openstack-tox-cover
+
 - job:
     name: neutron-fwaas-networking-midonet-cross-py35
     parent: openstack-tox-py35