add pyzmq to travis
add pyzmq to travis

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