Compat fix in resample for pandas 0.18.0
Compat fix in resample for pandas 0.18.0

mrocklin/dask,dask/dask,chrisbarber/dask,gameduell/dask,ContinuumIO/dask,cowlicks/dask,jakirkham/dask,ContinuumIO/dask,jcrist/dask,jakirkham/dask,blaze/dask,mrocklin/dask,mraspaud/dask,blaze/dask,dask/dask,mraspaud/dask,mikegraham/dask,cpcloud/dask,jcrist/dask