message: fix props.key error, explicit DonutSlice casting
diff: @@ -24,7 +24,7 @@ const DonutChart = props => {
  .outerRadius(radius)
  const slices = childList.map((child, i) => {
  - return <DonutSlice {...child.props} d={arc(arcData[i])} key={child.props.key} />
  + return React.cloneElement(child, {d: arc(arcData[i])})
  })
  return (
  