ci: Add helper script

ci: Add helper script

This is intended to be perform a number of CI-related operations
that are currently implemented in various different scripts
written in various different programming languages.

Eventually, all existing functionality will be reimplemented in
Python and made available through this single entry point; for
now, let's start with a very basic skeleton.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>