replace vdsm_master_unit-tests_created with its mock-based version

[Dan Kenigsberg]

With three ugly masking patches merged and propsed in
https://gerrit.ovirt.org/#/q/status:open+project:vdsm+branch:master+topic:unbreak_test_ci
the new vdsm_master_unit-tests_created_staging is passing with success.

Please take it out of "staging", disable the puppet-based
vdsm_master_unit-tests_created, and make it mark a fat -1 on any patch
breaking it.

We[*] shall work to unbreak the skipped patches in async.

Regards,
Dan.

[*] mostly the CCed