Make note of Docker user breaking change (#6562)
Make note of Docker user breaking change (#6562)

We changed the default user from root to nobody. This will change the
default for `--mesos_user`.

JIRA Issues: MARATHON-8438
gsantovena/marathon,gsantovena/marathon,mesosphere/marathon,mesosphere/marathon,mesosphere/marathon,mesosphere/marathon,gsantovena/marathon,gsantovena/marathon,mesosphere/marathon,gsantovena/marathon