Use openstack-tox-cover template

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

Change-Id: I11ca9d9454d69e10e3c881ce85b6c287f57900bf

zuul.d/projects.yaml

@@ -4,6 +4,7 @@
     templates:
       - check-requirements
       - periodic-stable-jobs-neutron
+      - openstack-cover-jobs
       - openstack-lower-constraints-jobs
       - openstack-python-jobs
       - openstack-python35-jobs
@@ -59,7 +60,6 @@
               - ^tools/.*$
               - ^(test-|)requirements.txt$
               - ^tox.ini$
-        - openstack-tox-cover
     gate:
       queue: octavia
       jobs:
@@ -96,7 +96,6 @@
               - ^tools/.*$
               - ^(test-|)requirements.txt$
               - ^tox.ini$
-        - openstack-tox-cover
     experimental:
       jobs:
         - octavia-v1-dsvm-scenario-lxd