Fix tests for Django 2.0.

.travis.yml

@@ -22,7 +22,12 @@ env:
 # install dependencies
 install:
   - pip install -r requirements-debug.txt
-  - pip install Django==$DJANGO_VERSION
+  - |
+    if [[ $DJANGO_VERSION =~ ^2.*$ && $TRAVIS_PYTHON_VERSION == "2.7" ]]; then
+      echo "Installing Django 2 in python 2 will fail. Keep the installed one"
+    else
+      pip install Django==$DJANGO_VERSION
+    fi
 
 # print pip packages
 before_script:

tests/settings.py

@@ -41,13 +41,24 @@
     'tests.test_app'
 ]
 
+# For version of Django smaller than 1.10
 MIDDLEWARE_CLASSES = [
     'django.middleware.security.SecurityMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
-    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+]
+
+# For versions of Django bigger or equal than 1.10
+MIDDLEWARE = [
+    'django.middleware.security.SecurityMiddleware',
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
     'django.middleware.clickjacking.XFrameOptionsMiddleware',
 ]