Add support for test updates on SLES12 SP3
Add support for test updates on SLES12 SP3

Now that SP3 is released, we should start using the test updates.

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