replace module-level ipcluster with contextmanager
replace module-level ipcluster with contextmanager

blaze/dask,PhE/dask,ssanderson/dask,vikhyat/dask,dask/dask,cpcloud/dask,jayhetee/dask,pombredanne/dask,simudream/dask,simudream/dask,wiso/dask,gameduell/dask,ssanderson/dask,blaze/dask,mrocklin/dask,clarkfitzg/dask,vikhyat/dask,ContinuumIO/dask,clarkfitzg/dask,mraspaud/dask,jayhetee/dask,jcrist/dask,PhE/dask,jcrist/dask,cowlicks/dask,jakirkham/dask,freeman-lab/dask,wiso/dask,mrocklin/dask,dask/dask,mraspaud/dask,mikegraham/dask,pombredanne/dask,chrisbarber/dask,jakirkham/dask,ContinuumIO/dask,freeman-lab/dask