fix stream close calls in dask
fix stream close calls in dask

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