TestRandomString was calling the wrong setUp
TestRandomString was calling the wrong setUp

Just incorrect usage of super(). This was bypassing HeatTestCase.setUp()
and causing extra logs to be printed.

Change-Id: I6f77cce53b971b14637e8705c3f73993ac458550
Partial-bug: 1281226

redhat-openstack/heat,cwolferh/heat-scratch,srznew/heat,jasondunsmore/heat,rdo-management/heat,rh-s/heat,steveb/heat,maestro-hybrid-cloud/heat,maestro-hybrid-cloud/heat,cwolferh/heat-scratch,jasondunsmore/heat,dragorosson/heat,rh-s/heat,redhat-openstack/heat,takeshineshiro/heat,takeshineshiro/heat,noironetworks/heat,noironetworks/heat,cryptickp/heat,pratikmallya/heat,dims/heat,rdo-management/heat,cryptickp/heat,srznew/heat,openstack/heat,gonzolino/heat,openstack/heat,gonzolino/heat,pshchelo/heat,dims/heat,miguelgrinberg/heat,dragorosson/heat,steveb/heat,pratikmallya/heat,pshchelo/heat,miguelgrinberg/heat