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: I8d8b49d6256c7f7adb05d4c3c9f5b2aae3af6105
diff --git a/.zuul.yaml b/.zuul.yaml
index 1dbebef..66339eb 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -172,6 +172,8 @@
 
 - project:
     templates:
+      - openstack-cover-jobs
+      - openstack-lower-constraints-jobs
       - openstack-python36-jobs
       - openstack-python-jobs
       - openstack-python35-jobs
@@ -187,12 +189,8 @@
         - patrole-py35-member
         - patrole-multinode-admin
         - patrole-multinode-member
-        - openstack-tox-lower-constraints
         - patrole-plugin-admin
         - patrole-plugin-member
-        - openstack-tox-cover:
-            voting: false
-
     gate:
       jobs:
         - patrole-admin