Configure tests for Django 2.2

src/auditlog_tests/tests.py

@@ -576,6 +576,8 @@ class CharfieldTextfieldModelTest(TestCase):
 
 class PostgresArrayFieldModelTest(TestCase):
 
+    databases = {'default', 'postgres'}
+
     def setUp(self):
         self.obj = PostgresArrayFieldModel.objects.create(
             arrayfield=[PostgresArrayFieldModel.RED, PostgresArrayFieldModel.GREEN],

tox.ini

@@ -5,6 +5,7 @@ envlist =
     {py27,py34,py35,py36}-django-111
     {py34,py35,py36}-django-20
     {py35,py36}-django-21
+    {py35,py36}-django-22
 
 [testenv]
 setenv =
@@ -16,6 +17,7 @@ deps =
     django-111: Django>=1.11,<2.0
     django-20: Django>=2.0,<2.1
     django-21: Django>=2.1,<2.2
+    django-22: Django>=2.2,<2.3
     -r{toxinidir}/requirements-test.txt
 basepython =
     py36: python3.6