reversed drop order to be consistent with instructions

Databases/dvdstore_500mb/6_dropAllData.monetdb.sql

 SET SCHEMA ds2;
-DROP TABLE ds2.categories CASCADE;
-DROP TABLE ds2.customers CASCADE;
-DROP TABLE ds2.inventory CASCADE;
-DROP TABLE ds2.orders CASCADE;
+-- drop tables in reversed order
+DROP TABLE ds2.reorder CASCADE;
 DROP TABLE ds2.products CASCADE;
-DROP TABLE ds2.cust_hist CASCADE;
+DROP TABLE ds2.orders CASCADE;
 DROP TABLE ds2.orderlines CASCADE;
-DROP TABLE ds2.reorder CASCADE;
+DROP TABLE ds2.inventory CASCADE;
+DROP TABLE ds2.customers CASCADE;
+DROP TABLE ds2.cust_hist CASCADE;
+DROP TABLE ds2.categories CASCADE;
+-- set schema of ds2 user to default
 ALTER USER "ds2" SET SCHEMA "sys";
 SET SCHEMA sys;
 DROP SCHEMA ds2;