Use templates for cover and lower-constraints

Small cleanups:

* Use openstack-tox-cover template, this runs the cover job
  in the check queue only. Remove individual cover jobs.
* Use openstack-lower-constraints-jobs template, remove individual
  jobs.
* Sort list of templates

Change-Id: I36081bfcc9e4cd393110c3fb6027048d57f925ad

zuul.d/project.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
       - periodic-stable-jobs
-      - check-requirements
+      - publish-openstack-docs-pti
       - release-notes-jobs-python3
     check:
       jobs:
@@ -29,8 +31,6 @@
             voting: false
         - ironic-tempest-dsvm-pxe_ipmitool-postgres:
             voting: false
-        - openstack-tox-lower-constraints
-        - openstack-tox-cover
     gate:
       queue: ironic
       jobs:
@@ -47,13 +47,8 @@
         - ironic-tempest-dsvm-ipa-wholedisk-bios-agent_ipmitool-tinyipa
         - ironic-tempest-dsvm-ipa-wholedisk-bios-agent_ipmitool-tinyipa-indirect
         - ironic-tempest-dsvm-ipa-partition-bios-agent_ipmitool-tinyipa-indirect
-        - openstack-tox-lower-constraints
-        - openstack-tox-cover
     experimental:
       jobs:
         - ironic-dsvm-functional
         - ironic-tempest-dsvm-parallel
         - ironic-tempest-dsvm-pxe_ipa-full
-    post:
-      jobs:
-        - openstack-tox-cover