Merge branch '50-remove-person-from-group-if-registration-is-retraced' into 'master'

Resolve "Remove person from group if registration is retraced"

Closes #50

See merge request !53

aleksis/apps/paweljong/models.py

@@ -357,12 +357,12 @@ class EventRegistration(ExtensibleModel):
             raise ValidationError(_("Person is already checked in!"))
 
     def retract(self):
-        # Remove person from group
-        self.event.linked_group.members.remove(self.person)
         # Mark registration as retracted
         self.retracted = True
         self.retracted_date = datetime.today()
         self.save()
+        # Remove person from group
+        self.event.linked_group.members.remove(self.person)
 
     def get_person(self):
         return self.person