keyserver and keys mandatory about distrobuilder HOT 2 CLOSED

So it's going to have to depend on the source being used.
Right now we have:

• alpine-http
• archlinux-http
• centos-http
• debootstrap
• ubuntu-http

Debootstrap shouldn't require a set of GPG keys to be passed as it contains a number of them internally. So if none are specified, the built-in keyring should be used and if the archive isn't signed by one of those keys, it will fail.

For the http downloaders, I'd like us to require them to either be https downloads or be validated by GPG, effectively preventing any unsafe downloads (as that was a big issue with the old template scripts that we're trying to make sure is fixed with distrobuilder).

from distrobuilder.

That was fast! Let some of these to me @monstermunchkin ;)

from distrobuilder.