add remove_client operation to scheduler
add remove_client operation to scheduler

Just logs for now

amosonn/distributed,dask/distributed,mrocklin/distributed,blaze/distributed,amosonn/distributed,broxtronix/distributed,mrocklin/distributed,mrocklin/distributed,amosonn/distributed,blaze/distributed,broxtronix/distributed,dask/distributed,broxtronix/distributed,dask/distributed,dask/distributed