Added missing test for rally.cmd.main.task.results
Added missing test for rally.cmd.main.task.results

Unit test for ‘results’ method in TaskCommands class was missing
followed advices from Ilya Kharin

Change-Id: I5a4f110933d855994172716b3607b0ef5e24599f

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