Rework the DNS name forging

[ogajduse]

Currently we have the following method for creating FQDN from the IP.

def get_FQDN_from_IP(ip):
    # If we want to support old version of OpenStack, we have to update this function and
    # solve it via serviceman
    return "ci-vm-{0}-{1}-{2}-{3}.hosted.upshift.rdu2.redhat.com".format(*ip.split("."))

I really think that there should be any other way doing this.
I am thinking of config file containing some entry like:

FQDN=ci-vm-{0}-{1}-{2}-{3}.hosted.upshift.rdu2.redhat.com

[jhutar]

PR was merged, so I will close this.

[ogajduse]

I meant that we should come up with another way, different from the current state. Reopeninig