Upgrade to Django 2.1 (#710)

* Upgrade to Django 2.0

* more models

* i18n foo

* Update setup.py

* Fix Sentry exception PRETIXEU-JC

* Enforce slug uniqueness

* Import sorting

* Upgrade to Django 2.1

* Travis config

* Try to fix PostgreSQL failure

* Smaller test matrix

* staticfiles→static

* Include request in all authenticate() calls

src/pretix/multidomain/middlewares.py

@@ -7,9 +7,9 @@ from django.contrib.sessions.middleware import (
 )
 from django.core.cache import cache
 from django.core.exceptions import DisallowedHost
-from django.core.urlresolvers import set_urlconf
 from django.http.request import split_domain_port
 from django.middleware.csrf import CsrfViewMiddleware as BaseCsrfMiddleware
+from django.urls import set_urlconf
 from django.utils.cache import patch_vary_headers
 from django.utils.deprecation import MiddlewareMixin
 from django.utils.http import cookie_date