Pass ISO from the CLI, always.
import string split filter
Tag instance with more build params

Makes use of the ansible-string-split-filter submodule.
Nightly builds into AMI

Meant to be run as a cron job, this will check dev.packages.vyos.net
for a new nightly helium amd64 iso and build an AMI for it, but only
if it hasn't been done already.