Test constraints for release-notes

Add new job for testing that constraints work with release notes.
This job runs on master, so let's run it directly on xenial.

Change-Id: Iec2af9380534672786ef36fed74b374f99c30859

jenkins/jobs/openstack-publish-jobs.yaml

@@ -84,6 +84,39 @@
           excludes: ''
       - console-log
 
+- job-template:
+    name: '{name}-releasenotes-test'
+    node: ubuntu-xenial
+
+    builders:
+      - print-template-name:
+          template-name: "{template-name}"
+      - zuul-git-branch-prep-upper-constraints:
+          branch: master
+      - install-distro-packages
+      - revoke-sudo
+      - shell: |
+          #!/bin/bash -xe
+          #
+          # When building the release notes after a patch merges we
+          # always want to build from master. Reno will find release
+          # notes on other branches and insert them into the right
+          # places in the documentation build, but only master has all
+          # of the appropriate branch-specific input files for
+          # Sphinx. The branch-git-prep builder checks out the
+          # repository where the current patch just merged, but it
+          # honors zuul configuration variables that may cause it to
+          # check out a patch merged into a stable branch. So, reset
+          # what we've checked out to master.
+          #
+          git checkout origin/master
+      - tox:
+          envlist: 'releasenotes'
+
+    publishers:
+      # TODO(jaegerandi): Add publishing
+      - console-log
+
 
 - job-template:
     name: 'gate-{name}-releasenotes'

jenkins/jobs/projects.yaml

@@ -5124,6 +5124,7 @@
           service: compute
       - api-ref-jobs:
           service: compute
+      - '{name}-releasenotes-test'
 
 - project:
     name: nova-docker

zuul/layout.yaml

@@ -8897,6 +8897,7 @@ projects:
       - gate-tempest-dsvm-full-devstack-plugin-ceph
     post:
       - nova-coverage-db
+      - nova-releasenotes-test
     experimental:
       - gate-tempest-dsvm-nova-v20-api
       - gate-grenade-dsvm-forward