export overloaded toJSON, make appveyor/windows happy
export overloaded toJSON, make appveyor/windows happy

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