Read shape datasets from DSS + Functional Tests

The geocoding route will now automatically read the region dataset from soda-fountain into the cache if the entry does not already exist.

A functional end-to-end test is added. It uses WireMock to provide a live HTTP service as a mock for soda-fountain, complete with ZK/Curator service registration.  This enables us to fully test the SodaFountainClient.

A test route to clear the cache of all regions also is added.

TODO: still need to update the thirdparty-utils dependency version, pending a merge and release of the GeoJSON parser there.