Added Docker instructions to the README.
Added Docker instructions to the README.

meteorhacks/docker-librato,qwaya/docker-logentries,edyn/docker-docker-stats-statsd,meteorhacks/docker-librato,dberesford/docker-logentries,brandedme/librato,mihaidma/docker-logentries,edyn/docker-docker-stats-statsd,rosskukulinski/docker-swarm-monitoring,rosskukulinski/docker-swarm-monitoring,jayfk/docker-logentries,jaydeep17/docker-logentries,StephenHynes7/docker-logentries,zvelo/docker-logentries,zvbuhl/docker-logentries,secondrotation/docker-logentries,logentries/docker-logentries,brandedme/librato,pelger/docker-logentries