Support partitioning for FK (#79)

Author: mfvanek

sql/foreign_keys_without_index.sql

@@ -18,6 +18,7 @@ from
     inner join pg_catalog.pg_attribute col on col.attrelid = c.conrelid and col.attnum = u.attnum
 where
     c.contype = 'f' and
+    c.conparentid = 0 and c.coninhcount = 0 and /* not a constraint in a partition */
     nsp.nspname = :schema_name_param::text and
     not exists(
         select 1