Import bounding box + geometries from Geonames

[riordan]

Geonames has a large number of places that it represents as polygons.

With the Pelias Who's on First release, we now support bounding boxes in the schema, which is done by the importers for Who's on First and OpenStreetMap, we should do the same for Geonames.

Importantly, this'll bring consistency for search results of admin areas where some are returned from Who's on First and others are returned from Geonames (e.x. New York, NY).

ps

And then eventually store the geometries, yeah?

[riordan]

As it turns out, Geonames is only releasing polygons for countries at this time, and is considering lower administrative areas as a premium option.

Instead, it just make sense to add more geonames concordances to Who's on First so we can skip their import here.