Slight refactoring of the testcase for Tester.run()
Slight refactoring of the testcase for Tester.run()

This is a slight refactoring of the test case for the utils.Tester.run()
method which removes code duplicate and adds one extra assertion (the method
is a really central one for Rally and should be carefully tested).

Blueprint test-engine

Change-Id: Ibcef9637b17d181dd4cff5656d510de24a600a1c

pandeyop/rally,varunarya10/rally,pyKun/rally,afaheem88/rally,amit0701/rally,ytsarev/rally,yeming233/rally,redhat-openstack/rally,group-policy/rally,go-bears/rally,eayunstack/rally,pandeyop/rally,vponomaryov/rally,group-policy/rally,yeming233/rally,pyKun/rally,openstack/rally,group-policy/rally,gluke77/rally,go-bears/rally,amit0701/rally,vganapath/rally,openstack/rally,gluke77/rally,amit0701/rally,ytsarev/rally,vefimova/rally,vganapath/rally,aforalee/RRally,vganapath/rally,openstack/rally,gluke77/rally,eayunstack/rally,aforalee/RRally,vefimova/rally,cernops/rally,eayunstack/rally,paboldin/rally,varunarya10/rally,vganapath/rally,vponomaryov/rally,gluke77/rally,aplanas/rally,afaheem88/rally,paboldin/rally,openstack/rally,shdowofdeath/rally,eonpatapon/rally,eonpatapon/rally,shdowofdeath/rally,aplanas/rally,cernops/rally,redhat-openstack/rally,paboldin/rally