message: Update MessagePanel test to account for new DOM structure
diff: @@ -309,7 +309,7 @@ describe('MessagePanel', function() {
  const rm = TestUtils.findRenderedDOMComponentWithClass(res, 'mx_RoomView_myReadMarker_container');
  // it should follow the <li> which wraps the event tile for event 4
  - const eventContainer = ReactDOM.findDOMNode(tiles[4]).parentNode;
  + const eventContainer = ReactDOM.findDOMNode(tiles[4]);
  expect(rm.previousSibling).toEqual(eventContainer);
  });
  @@ -365,7 +365,7 @@ describe('MessagePanel', function() {
  const tiles = TestUtils.scryRenderedComponentsWithType(
  mp, sdk.getComponent('rooms.EventTile'));
  const tileContainers = tiles.map(function(t) {
  - return ReactDOM.findDOMNode(t).parentNode;
  + return ReactDOM.findDOMNode(t);
  });
  // find the <li> which wraps the read marker
  