Make Horizon integration tests non-voting
Make Horizon integration tests non-voting

The Horizon integration tests have been incredibly unstable recently. We
are making them temporarily non-voting to allow changes in without
constant rechecks.

Change-Id: I9e22a6b9af83163b544bb5dd1530b9ad150a0ecf

openstack-infra/project-config,openstack-infra/project-config,Tesora/tesora-project-config,Tesora/tesora-project-config