drivers.text.writer file sizes

We tested the drivers.text.writer on a 2693573 point lasfile, keeping the X, Y, Z, Red, Green, Blue, Intensity, PointSourceId, and Classification dimensions. The output file size comparisons are below, and the complete pipeline used to generate these files can be found here.

	unzipped	gzip
CSV	129MB	31MB
GeoJSON	666MB	64MB

GeoJSON creates a large file, but it compresses well.