Fallback to using pydap if netcdf4 is not available
Fallback to using pydap if netcdf4 is not available

NicWayand/xray,shoyer/xray,chunweiyuan/xarray,drewokane/xray,markelg/xray,hetland/xray,cpaulik/xray,jhamman/xarray,markelg/xray,hetland/xray,shoyer/xarray,jhamman/xarray,pydata/xarray,rabernat/xray,jhamman/xray,pydata/xarray,rabernat/xray,xray/xray,jcmgray/xarray,pydata/xarray,kjordahl/xray,kjordahl/xray,cpaulik/xray,clarkfitzg/xray,jhamman/xarray,clarkfitzg/xray,shoyer/xarray,petercable/xray,markelg/xray