This is the counterpart of 'debian-branch' (basically identical to that)
to not confuse rpm maintainers.
Also, adds this option to gbp-clone and gbp-pull commands (as an
alternative to the 'debian-branch option), which are usable for RPM in
their current form.
Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>