Prepare tests for the Ironic combined service

In I51bf7226aea145dc7c8fd93d61caa233ca16c9c9 we are introducing a way to
run Ironic API and conductor in one process. In the Bifrost change
I9faecfe6ece6d3c35396e3378c1e3930a487e130 we are switching Bifrost to
it, which breaks the Kolla job.

This change makes get_logs.sh aware of the new service. Also drop
RabbitMQ since Bifrost hasn't supported it for a while already.

Change-Id: I30ac6bd4332dacbdce1f5e25bd6a97d2982b208e