Add keyword arguments to PermissionNamespace uses

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/document_signatures/permissions.py

@@ -5,7 +5,7 @@ from django.utils.translation import ugettext_lazy as _
 from mayan.apps.permissions import PermissionNamespace
 
 namespace = PermissionNamespace(
-    'document_signatures', _('Document signatures')
+    name='document_signatures', _('Document signatures')
 )
 
 permission_document_version_sign_detached = namespace.add_permission(