Moved core plugins to the new URL API

src/pretix/plugins/paypal/urls.py

@@ -0,0 +1,10 @@
+from django.conf.urls import include, url
+
+from .views import abort, success
+
+event_patterns = [
+    url(r'^paypal/', include([
+        url(r'^abort/$', abort, name='abort'),
+        url(r'^return/$', success, name='return'),
+    ])),
+]