Test multi-cast messaging between VMs.

Test multi-cast messages are delivered bewteen two VMs
using IPv4 through the same tenant network.

This new test scenario requires advanced image to be run as
it needs to run python3 scripts and python3 is not available
on Cirros.

Co-authored-by: Slawek Kaplonski <skaplons@redhat.com>

Change-Id: Idd1589adbff6e556290f43fabbb8a23737a34adf
3 files changed