Images do not handle multiple network interfaces correctly

[doublej472]

We are already running into issues with multiple network cards not being configured properly in the Mitaka cluster as can be seen here. We should be able to create a service inside the OS images that properly handles multiple network cards.

Here is a blog post about one approach to solving this issue: https://barakme.wordpress.com/2015/05/15/a-multi-network-friendly-openstack-cloud-image-with-netplugd/.

This should also be tested for in openstack-taster so we know that the images work with multiple networks.