Install GDAL, PROJ.4 and libxml2 on Travis CI
Install GDAL, PROJ.4 and libxml2 on Travis CI

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