Enabled python 3.8 in test matrix

.travis.yml

@@ -3,6 +3,7 @@ python:
   - '3.5'
   - '3.6'
   - '3.7'
+  - '3.8'
 
 env:
   global:
@@ -70,5 +71,5 @@ deploy:
   distributions: sdist bdist_wheel
   on:
     tags: true
-    python: '3.7'
+    python: '3.8'
     condition: "$DB = POSTGRESQL"

modoboa/admin/tests/test_need_dovecot_update.py

@@ -19,20 +19,21 @@ class NeedDovecotUpdateTestCase(ModoTestCase):
     @classmethod
     def setUpTestData(cls):
         """Create test data."""
-        super(NeedDovecotUpdateTestCase, cls).setUpTestData()
+        super().setUpTestData()
         factories.populate_database()
 
     def setUp(self):
         """Initiate initial env."""
-        super(NeedDovecotUpdateTestCase, self).setUp()
+        super().setUp()
         self.workdir = tempfile.mkdtemp()
+        self.localconfig.need_dovecot_update = False
+        self.localconfig.save()
 
     def tearDown(self):
         """Reset test env."""
         shutil.rmtree(self.workdir)
 
     def test_update_dovecot_update_state_valid_form(self):
-        self.assertFalse(self.localconfig.need_dovecot_update)
         url = reverse("core:parameters")
         settings = SETTINGS_SAMPLE.copy()
         response = self.client.post(url, settings, format="json")