added reference for point in lasso func
added reference for point in lasso func

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