fix test that was too subject to random data
fix test that was too subject to random data

mpgerlek/PDAL-old,verma/PDAL,jwomeara/PDAL,radiantbluetechnologies/PDAL,DougFirErickson/PDAL,mpgerlek/PDAL-old,boundlessgeo/PDAL,boundlessgeo/PDAL,Sciumo/PDAL,jwomeara/PDAL,Sciumo/PDAL,verma/PDAL,mtCarto/PDAL,mpgerlek/PDAL-old,lucadelu/PDAL,lucadelu/PDAL,mtCarto/PDAL,radiantbluetechnologies/PDAL,lucadelu/PDAL,verma/PDAL,verma/PDAL,verma/PDAL,boundlessgeo/PDAL,radiantbluetechnologies/PDAL,DougFirErickson/PDAL,DougFirErickson/PDAL,Sciumo/PDAL,mpgerlek/PDAL-old,Sciumo/PDAL,DougFirErickson/PDAL,jwomeara/PDAL,lucadelu/PDAL,verma/PDAL,mtCarto/PDAL,mtCarto/PDAL,boundlessgeo/PDAL,jwomeara/PDAL,radiantbluetechnologies/PDAL,verma/PDAL