Add a test that makes a bit of sense

client/sql/10_admin0_test.sql

@@ -0,0 +1,12 @@
+-- Mock the server function
+CREATE OR REPLACE FUNCTION cdb_geocoder_server.geocode_admin0_polygons(user_id name, tx_id bigint, country_name text)
+RETURNS Geometry AS $$
+BEGIN
+  RAISE NOTICE 'cbd_geocoder_server.geocode_admin0_polygons invoked with params (%, %, %)', user_id, 'some_transaction_id', country_name;
+  RETURN NULL;
+END;
+$$ LANGUAGE 'plpgsql';
+
+
+-- Exercise the public and the proxied function
+SELECT cdb_geocoder_client.geocode_admin0_polygons('Spain');