add _visualize method to dask.bag
add _visualize method to dask.bag

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