Fix the tempest setup process for icehouse/juno

This patch fixes the setup process of the nodes
It removes the setup of openstack elements for icehouse/juno
It fixes the default security rules that blocks initial communication
It removes the need to download the cirros image for icehouse/juno
as the tempest auto configuration tool does it anyway.

Change-Id: Ide366d7a13465f945458d657cc51d54280668615