Add uid to nanny queue communications (#1880)
Add uid to nanny queue communications (#1880)

We seemed to be getting crossed communications in multiprocessing queues
Now we explicitly pass around a unique key and disregard unrelated
communications
blaze/distributed,mrocklin/distributed,dask/distributed,mrocklin/distributed,dask/distributed,blaze/distributed,dask/distributed,mrocklin/distributed,dask/distributed