qa_crowbarsetup: Allow extra repo for testing
qa_crowbarsetup: Allow extra repo for testing

When setting $QUICKSTART_DEBUG and the new env var
$cloudsource_extra to a zypper repo, packages from this
repo will be used.
This is useful when testing locally with some packages which
are not yet merged.

vmoravec/automation,aspiers/automation,aspiers/automation,SUSE-Cloud/automation,SUSE-Cloud/automation,vmoravec/automation,aspiers/automation,gosipyan/automation,gosipyan/automation,vmoravec/automation,SUSE-Cloud/automation,gosipyan/automation,gosipyan/automation,aspiers/automation,vmoravec/automation,SUSE-Cloud/automation