Fix style

__init__.py

@@ -2,9 +2,10 @@
 # The COPYRIGHT file at the top level of this repository contains the full
 # copyright notices and license terms.
 from trytond.pool import Pool
-from .invoice import *
+from . import invoice
+
 
 def register():
     Pool.register(
-        Invoice,
+        invoice.Invoice,
         module='account_invoice_visible_payments', type_='model')

tests/test_account_invoice_visible_payments.py

@@ -15,4 +15,4 @@ def suite():
     suite = trytond.tests.test_tryton.suite()
     suite.addTests(unittest.TestLoader().loadTestsFromTestCase(
         AccountInvoiceVisiblePaymentsTestCase))
-    return suite
+    return suite