fix for scatter model missed attribute
fix for scatter model missed attribute

bloomberg/bqplot,ssunkara1/bqplot,bloomberg/bqplot,rmenegaux/bqplot,dmadeka/bqplot,bloomberg/bqplot,rmenegaux/bqplot,ChakriCherukuri/bqplot,SylvainCorlay/bqplot,ssunkara1/bqplot,ChakriCherukuri/bqplot,dmadeka/bqplot,ChakriCherukuri/bqplot,SylvainCorlay/bqplot,SylvainCorlay/bqplot