Remove cluster member

Remove node from a cluster. See https://trello.com/c/xarZEs6g/846-ha-support-removing-nodes-from-clusters

Originally https://github.com/crowbar/barclamp-pacemaker/pull/100, but rebased and requested against master 

https://github.com/crowbar/barclamp-crowbar/pull/1011 is needed so the remove role get correctly deleted after it is used once.
I might be wrong, but I think that pacemaker automatically does this.