Switch to version 4.6 about coreos-iso-maker

[lukyky414]

I'd like to add:

The difference on v4.6 is that the iso is a live version of coreos.

First change: the 'iso_name' now is '-live' instead of '-installer'.

Second: there is no need to use a image file together with the installation iso.
It is possible to add some code, to automatically ignore the 'coreos.inst.image_url' parameter if 'rhcos_bios' is not provided.

[chuckersjp]

Oooh....thanks for that.

Let me try an figure out how to put that in there. There is a lot of new things with 4.6 that don't seem to be documented.
Hopefully I will get to it later today.

[lukyky414]

Resolved in Pull Request #13 .