Add node deletion tests
Add node deletion tests

Assert that we can delete a node and a new one is created, also that a
failed deletion of a node does not prevent this.

Change-Id: I59d3d7292bd405e084defd02b99ac1565277d501

citrix-openstack/nodepool,seandst/nodepool,Tesora/tesora-nodepool,seandst/nodepool,citrix-openstack/nodepool,Tesora/tesora-nodepool