implicit mesos-local support in scheduler drivers

[James Peach]

Hi all,

I found recently, that the Mesos scheduler drivers will implicitly spin up a 
`mesos-local` cluster for testing if your scheduler uses the Mesos scheduler 
drivers, specifies “local” as the master, and exports “MESOS_" environment 
variables to configure the master. Do any scheduler authors use this? If so, 
can you desribe the workflow?

thanks,
James