FIX/UPD: tests are OK with python3.

dav_base/config/apps.py

@@ -21,10 +21,10 @@ class DefaultSetting(object):
         if hasattr(self, 'validator') and self.validator is not None:
             if callable(self.validator):
                 if not self.validator(value):
-                    raise ImproperlyConfigured("Validator callback {clb} returned False".format(clb=self.validator))
+                    raise ImproperlyConfigured('Validator callback {clb} returned False'.format(clb=self.validator))
             else:
                 if not re.search(self.validator, value):
-                    raise ImproperlyConfigured("Does not match /{re}/".format(re=self.validator))
+                    raise ImproperlyConfigured('Does not match /{re}/'.format(re=self.validator))
 
 
 class AppSettings(object):
@@ -44,7 +44,7 @@ class AppSettings(object):
                 except ImproperlyConfigured as e:
                     msg = 'Invalid value of {key} in {module}: {cause}'.format(key=default.key_name,
                                                                                module=settings_name,
-                                                                               cause=e.message)
+                                                                               cause=e)
                     raise ImproperlyConfigured(msg)
                 setattr(self, default.name, value)
             elif isinstance(default.value, ImproperlyConfigured):