message: When dispatching view_[my_]group[s], reset RoomViewStore
  so that RoomTiles are not highlighted when the user is looking at MyGroups or GroupView
diff: @@ -72,6 +72,13 @@ class RoomViewStore extends Store {
  case 'view_room':
  this._viewRoom(payload);
  break;
  + case 'view_my_groups':
  + case 'view_group':
  + this._setState({
  + roomId: null,
  + roomAlias: null,
  + });
  + break;
  case 'view_room_error':
  this._viewRoomError(payload);
  break;
  