use leader.mesos instead of master.mesos (#486)
use leader.mesos instead of master.mesos (#486)

As per gitter discussion with @mhausenblas
aloismayr/universe,madanadit/universe,NimaVaziri/universe,dhilipkumars/universe,mesosphere/universe,kensipe/universe,titosand/universe,dhilipkumars/universe,BuoyantIO/universe,yuchaoran2011/universe,ksivask/universe,kensipe/universe,ksivask/universe,AppliedIS/universe,niteshch207/universe,ksivask/universe,niteshch207/universe,dbtucker/universe,niteshch207/universe,titosand/universe,titosand/universe,yuchaoran2011/universe,dhilipkumars/universe,dbtucker/universe,NimaVaziri/universe,AppliedIS/universe,BuoyantIO/universe,AppliedIS/universe,dbtucker/universe,madanadit/universe,mesosphere/universe,mwl/universe,BuoyantIO/universe,mwl/universe,kensipe/universe,NimaVaziri/universe,aloismayr/universe,aloismayr/universe,madanadit/universe,yuchaoran2011/universe