Use newer ipython for doc build
Use newer ipython for doc build

jhamman/xarray,markelg/xray,xray/xray,jhamman/xarray,markelg/xray,jhamman/xarray,pydata/xarray,markelg/xray,chunweiyuan/xarray,shoyer/xray,jhamman/xray,shoyer/xarray,shoyer/xarray,pydata/xarray,jcmgray/xarray,pydata/xarray