Switch CentOS to non-voting

There is currently a problem with CentOS builds which
is not common to the other distributions, but the issue
is blocking patches from merging.

Until the issue is resolved, we switch the job to a
non-voting job.

Change-Id: Ic410fe6fda279955fec2472413efaa96e7de3321
Related-Bug: #1773248

zuul.d/project.yaml

@@ -16,7 +16,10 @@
     check:
       jobs:
         - openstack-ansible-linters
-        - openstack-ansible-functional-centos-7
+        # TODO(odyssey4me):
+        # Restore this to voting once the blocking
+        # issue has been resolved.
+        - openstack-ansible-functional-centos-7-nv
         - openstack-ansible-functional-opensuse-423
         - openstack-ansible-functional-ubuntu-xenial
         # TODO(odyssey4me):
@@ -31,7 +34,10 @@
     gate:
       jobs:
         - openstack-ansible-linters
-        - openstack-ansible-functional-centos-7
+        # TODO(odyssey4me):
+        # Restore this once the blocking issue has
+        # been resolved.
+        #- openstack-ansible-functional-centos-7
         - openstack-ansible-functional-opensuse-423
         - openstack-ansible-functional-ubuntu-xenial
         # TODO(odyssey4me):