fix tests

tests/currency.py

@@ -3,7 +3,7 @@
 # The COPYRIGHT file at the top level of this repository contains the
 # full copyright notices and license terms.
 
-from trytond.tests.test_tryton import ModuleTestCase, with_transaction
+from trytond.tests.test_tryton import with_transaction
 from trytond.pool import Pool
 from trytond.modules.cashbook.model import CACHEKEY_CURRENCY, ENABLE_CACHE
 from datetime import date
@@ -11,10 +11,9 @@ from decimal import Decimal
 import time
 
 
-class CurrencyTestCase(ModuleTestCase):
-    'Test cache for currency'
-    module = 'cashbook'
-
+class CurrencyTestCase(object):
+    """ test currency
+    """
     @with_transaction()
     def test_currency_update_cache(self):
         """ add/update/del rate of currency, check cache