message: Add getCanonicalAlias to mock
diff: @@ -34,6 +34,7 @@ function mockRoom(roomId, members, serverACL) {
  return {
  roomId,
  + getCanonicalAlias: () => roomId,
  getJoinedMembers: () => members,
  getMember: (userId) => members.find(m => m.userId === userId),
  currentState: {
  