bump version to 0.2.6
bump version to 0.2.6

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