Add ability to add message for participation and improve participation

management interface

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

test/mobilizon/events/events_test.exs

@@ -110,8 +110,11 @@ defmodule Mobilizon.EventsTest do
       assert event.ends_on == DateTime.from_naive!(~N[2010-04-17 14:00:00Z], "Etc/UTC")
       assert event.title == "some title"
 
-      assert hd(Events.list_participants_for_event(event.id)).actor.id == actor.id
-      assert hd(Events.list_participants_for_event(event.id)).role == :creator
+      assert %Participant{} =
+               participant = hd(Events.list_participants_for_event(event.id).elements)
+
+      assert participant.actor.id == actor.id
+      assert participant.role == :creator
     end
 
     test "create_event/1 with invalid data returns error changeset" do