controller/tests: The DB used for auth must be test DB.

Since auth is initialised at the beginning it doesn't benefit from the change of the DB.
Therefore it was modifying the original DB rather than working on the test DB.

server/web2py/testRunner.py

@@ -61,6 +61,7 @@ for tablename in db.tables:  # Copy tables!
     test_db.define_table(tablename, *table_copy)
 
 db = test_db
+auth.db = test_db
 
 
 init_db(True)