import zuul job settings from project-config

This is a mechanically generated patch to complete step 1 of moving
the zuul job settings out of project-config and into each project
repository.

Because there will be a separate patch on each branch, the branch
specifiers for branch-specific jobs have been removed.

Because this patch is generated by a script, there may be some
cosmetic changes to the layout of the YAML file(s) as the contents are
normalized.

See the python3-first goal document for details:
https://governance.openstack.org/tc/goals/stein/python3-first.html

Change-Id: Icdb713cd0b5f04962cb7c79a349c359ad7db28da
Story: #2002586
Task: #24309

.zuul.yaml

@@ -1,19 +1,31 @@
 - project:
+    templates:
+      - check-requirements
+      - openstack-python-jobs-horizon
+      - openstack-python35-jobs-horizon
+      - publish-openstack-sphinx-docs
+      - release-notes-jobs
     check:
       jobs:
         - manila-ui-dsvm:
             voting: false
         - openstack-tox-lower-constraints:
             required-projects:
-              openstack/horizon
+              - openstack/horizon
         - horizon-openstack-tox-python3-django111
+        - horizon-openstack-tox-py27dj19
+        - horizon-openstack-tox-py27dj110
+        - openstack-tox-cover:
+            voting: false
     gate:
       jobs:
         - openstack-tox-lower-constraints:
             required-projects:
-              openstack/horizon
+              - openstack/horizon
         - horizon-openstack-tox-python3-django111
 
+        - horizon-openstack-tox-py27dj19
+        - horizon-openstack-tox-py27dj110
 - job:
     name: manila-ui-dsvm
     parent: legacy-dsvm-base