Use oslotest instead of common test module
Use oslotest instead of common test module

Module openstack.common.test is obsolete, so we should use
oslotest library instead of it.
Modified tests and common database code, new requirement added.

Change-Id: I853e548f11a4c3785eaf75124510a6d789536634

zzicewind/oslo.log,meganjbaker/oslo.log,openstack/oslo.log,magic0704/oslo.log