Wrong header written to shapes.txt

[nilsnolde]

The header for shapes.txt is missing the shape_dist_traveled field, while the data actually writes it, resulting in a broken CSV.

just_gtfs/include/just_gtfs/just_gtfs.h

Lines 200 to 205 in b7f7aba

	inline void write_shapes_header(std::ofstream & out)
	{
	std::vector<std::string> fields = {"shape_id", "shape_pt_lat", "shape_pt_lon",
	"shape_pt_sequence"};
	write_joined(out, std::move(fields));
	}