Adds cdb_geocoder_server.geocode_postalcode_point and tests

server/extension/sql/80_postalcode_point_test.sql

@@ -0,0 +1,14 @@
+-- Check that the public function is callable, even with no data
+-- It should return NULL
+SELECT cdb_geocoder_server.geocode_postalcode_point(session_user, txid_current(), '03204');
+
+-- Insert dummy data into ip_address_locations
+INSERT INTO global_postal_code_points (the_geom, iso3, postal_code, postal_code_num) VALUES (
+  '0101000020E61000000000000000E040408036B47414764840',
+  'ESP',
+  '03204',
+  3204
+);
+
+-- This should return the polygon inserted above
+SELECT cdb_geocoder_server.geocode_postalcode_point(session_user, txid_current(), '03204');