Test validating messages with references to GeoJson schema in both JS and python
Rather than encoding data in the same form as a GeoJson polygon coordinates linear ring, test referencing the GeoJson schema directly.
We could then test allowing things to be defined as a Feature or FeatureCollection although at least in the short term we probably want to keep things simple by linking things to types (waypoint=point, operating-area=polygon, transect=linestring
We can't use this unless it works in at least python and JS