Switch upgrade test to non-voting

The upgrade test is currently failing due to the test
implementation, rather than a failure to upgrade. The
issue is that UCA for queens is implemented and packages
are installed from there, before the pike UCA replaces
it and installs other packages. The mixed set is not
compatible with the version of libvirt-python that needs
to be built.

Until we can fix the job, let's allow other patches to
merge.

Change-Id: I349c39be84a360b4560fb6683d0e209cd18e85e7
(cherry picked from commit 13bbca5c23)

zuul.d/project.yaml

@@ -18,11 +18,17 @@
         - openstack-ansible-linters
         - openstack-ansible-functional-centos-7-nv
         - openstack-ansible-functional-ubuntu-xenial
-        - openstack-ansible-upgrade-ubuntu-xenial
+        # TODO(odyssey4me):
+        # Restore this to voting once the test is
+        # working again.
+        - openstack-ansible-upgrade-ubuntu-xenial-nv
         - openstack-ansible-lxd-ubuntu-xenial
     gate:
       jobs:
         - openstack-ansible-linters
         - openstack-ansible-functional-ubuntu-xenial
-        - openstack-ansible-upgrade-ubuntu-xenial
+        # TODO(odyssey4me):
+        # Restore this to voting once the test is
+        # working again.
+        #- openstack-ansible-upgrade-ubuntu-xenial
         - openstack-ansible-lxd-ubuntu-xenial