Revert changes to handle bytes attributes
Revert changes to handle bytes attributes

No longer needed now that the scipy backend decodes all attributes

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