Added tests for modifying and cancelling orders

src/tests/testdummy/ticketoutput.py

@@ -0,0 +1,18 @@
+import logging
+
+from django.http import HttpResponse
+from pretix.base.ticketoutput import BaseTicketOutput
+
+
+logger = logging.getLogger('tests.testdummy.ticketoutput')
+
+
+class DummyTicketOutput(BaseTicketOutput):
+    identifier = 'testdummy'
+    verbose_name = 'Test dummy'
+    download_button_text = 'Download test file'
+    download_button_icon = 'fa-print'
+
+    def generate(self, request, order):
+        response = HttpResponse(order.identity, content_type='text/plain')
+        return response