multinode_major_upgrade: enable Pacemaker
multinode_major_upgrade: enable Pacemaker

To improve testing coverage in upgrade CI job, add Pacemaker.

Change-Id: I855ed15642e28cdfda5a7cbd6ff6d01b591dff7e

openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates