ロード時に TimelineColumn render method でエラー

[Neustrashimy]

Windows 10 / Chrome 61.0.3163.79（Official Build）（64 ビット）
naumanni alpha-0.2-66-ga73e7f6

warning.js:36 Warning: Each child in an array or iterator should have a unique "key" prop. Check the render method of `TimelineColumn`. See https://fb.me/react-warning-keys for more information.
    in ColumnFilterText (created by TimelineColumn)
    in TimelineColumn (created by DragSource(TimelineColumn))
    in DragSource(TimelineColumn) (created by DropTarget(DragSource(TimelineColumn)))
    in DropTarget(DragSource(TimelineColumn)) (created by ColumnContainer)
    in div (created by ColumnContainer)
    in ColumnContainer (created by DragDropContext(ColumnContainer))
    in DragDropContext(ColumnContainer) (created by Dashboard)
    in div (created by Dashboard)
    in div (created by Dashboard)
    in IntlProvider (created by Dashboard)
    in Dashboard