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: I02d6a9d958fe688bed5f574fef410cb8be37f03f
Story: #2002586
Task: #24759

.zuul.yaml

@@ -1,4 +1,7 @@
 - project:
+    templates:
+      - openstack-python-jobs
+      - openstack-python35-jobs
     check:
       jobs:
         - refstack-client-devstack-tempestconf
@@ -8,6 +11,9 @@
         - refstack-client-devstack-tempestconf
         - openstack-tox-py35
 
+    post:
+      jobs:
+        - openstack-tox-cover
 - job:
     name: refstack-client-devstack-tempestconf
     parent: devstack
@@ -27,7 +33,7 @@
     vars:
       user: demo
       cloud_user: devstack
-      test_demo: True
+      test_demo: true
       cloud_admin: devstack-admin
     irrelevant-files:
       - config_tempest/tests/.*$