Add a silly test to the extension

geocoder/admin0/extension/expected/cdb_geocoder_admin0_test.out

@@ -0,0 +1,13 @@
+CREATE EXTENSION postgis;
+CREATE EXTENSION schema_triggers;
+CREATE EXTENSION plpythonu;
+CREATE EXTENSION cartodb;
+CREATE EXTENSION cdb_geocoder_admin0;
+-- Check that the synonym function is callable, should return NULL
+SELECT (admin0_synonym_lookup(Array['United States', 'ESP'])).*;
+       q       | adm0_a3 
+---------------+---------
+ United States | 
+ ESP           | 
+(2 rows)
+