Add more tests + Event.max_items_pre_order should be a settings

src/pretix/base/migrations/0011_remove_event_max_items_per_order.py

@@ -0,0 +1,18 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0010_auto_20150218_2048'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='event',
+            name='max_items_per_order',
+        ),
+    ]