Fedora/CentOS specific fixes in devstack engine
Fedora/CentOS specific fixes in devstack engine

Got following issues with Fedora and CentOS:

 * only tcp port 22 is open by default
 * requiretty is true in sudoers
 * no /sbin in $PATH

Change-Id: I7467864059512c1aee2645c0cba46a80db7a055b

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