Mesos Master/Slave Configuration Links in README Out of Date

[catherinetcai]

The Mesos Master and Slave README here is out of date. The Slave and Master configuration reference links are redirected from open.mesosphere.com and drops you to dcos.io. I looked through the DCOS docs, and I can't seem to find anything about how to configure them. I've had to reference http://mesos.apache.org/documentation/latest/configuration/ to figure out what commands to pass the Slaves for things like roles. Hoping this can get amended, thanks.