Add GeoJSON GQL types to wocky_api

[toland]

Ideally, we would like to start using GeoJSON as a standard way to express geographic locations within our GQL API. The first step to do that would be to include GQL types that represent the GeoJSON schema. Someone has already done that work for generic GQL, but we would need to translate that into Absinthe.

https://github.com/sogko/graphql-schemas/blob/master/geojson/schema.txt