Used isort to order all import statements

src/pretix/presale/views/__init__.py

@@ -1,8 +1,8 @@
-from itertools import groupby
 from datetime import timedelta
+from itertools import groupby
+
 from django.contrib.auth.views import redirect_to_login
 from django.core.urlresolvers import reverse
-
 from django.db.models import Q
 from django.utils.functional import cached_property
 from django.utils.timezone import now