TestInvoice was missing in TestSaleInvoiceMixin, so test methods were not used

on Sale Invoices


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@23758 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/tests/testInvoice.py

@@ -1845,7 +1845,7 @@ class TestSaleInvoiceMixin(TestInvoiceMixin,
 
 
 
-class TestSaleInvoice(TestSaleInvoiceMixin, ERP5TypeTestCase):
+class TestSaleInvoice(TestSaleInvoiceMixin, TestInvoice, ERP5TypeTestCase):
   """Tests for sale invoice.
   """
   RUN_ALL_TESTS = 1