added django 2.2, dropped django 2.0 and python 3.4

keeping in sync with https://www.djangoproject.com/download/#supported-versions

.travis.yml

@@ -1,7 +1,6 @@
 language: python
 python:
 - '2.7'
-- '3.4'
 - '3.5'
 - '3.6'
 # Enable 3.7 without globally enabling sudo and dist: xenial for other build jobs

dbtemplates/test_settings.py

@@ -18,12 +18,15 @@ DATABASES = {
 INSTALLED_APPS = [
     'django.contrib.contenttypes',
     'django.contrib.sites',
+    'django.contrib.sessions',
+    'django.contrib.messages',
     'django.contrib.admin',
     'django.contrib.auth',
     'dbtemplates',
 ]
 
-MIDDLEWARE_CLASSES = (
+MIDDLEWARE = (
+    'django.contrib.sessions.middleware.SessionMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
 )
@@ -41,6 +44,7 @@ TEMPLATES = [
             'loaders': TEMPLATE_LOADERS,
             'context_processors': [
                 'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
             ]
         }
     },

tox.ini

@@ -5,14 +5,13 @@ minversion = 1.8
 envlist =
     flake8-py{27,37},
     twine-check-py{27,37},
-    py{27,34,35,36}-dj111
-    py{34,35,36,37}-dj20
+    py{27,35,36}-dj111
     py{35,36,37}-dj21
+    py{35,36,37}-dj22
 
 [testenv]
 basepython =
     py27: python2.7
-    py34: python3.4
     py35: python3.5
     py36: python3.6
     py37: python3.7
@@ -24,6 +23,7 @@ deps =
     dj111: Django<2.0
     dj20: Django<2.1
     dj21: Django<2.2
+    dj22: Django<2.3
     djmaster: https://github.com/django/django/archive/master.tar.gz#egg=django
 
 commands =