Fix #515 -- Add check-in lists (#693)

* Data model and migration

* Some backwards compatibility

* CRUD for checkin lists

* Show and perform checkins

* Correct numbers in table and dashboard widget

* event creation and cloning

* Allow to link specific exports and pass options per query

* Play with the CSV export

* PDF export

* Collapse exports by default

* Improve PDF exporter

* Addon stuff

* Subevent stuff, pretixdroid tests

* pretixdroid tests

* Add CRUD API

* Test compatibility

* Fix test

* DB-independent sorting behavior

* Add CRUD and coyp tests

* Re-enable pretixdroid plugin

* pretixdroid config

* Tests & fixes

src/pretix/plugins/pretixdroid/__init__.py

@@ -12,6 +12,7 @@ class PretixdroidApp(AppConfig):
         name = _("pretixdroid API")
         author = _("the pretix team")
         version = version
+        visible = True
         description = _("This plugin allows you to use the pretixdroid Android app for your event.")
 
     def ready(self):