message: Kept interpolators if end unchanged
diff: @@ -28,9 +28,10 @@ class Motion extends React.Component {
  return items
  .map(item => {
  var end = !dataByKey[item.key] ? leave(item.data) : update(item.data);
  - var interpolators = this.getInterpolators(item.style, end);
  const equal = areEqual(item.style, end);
  - return {...item, end, interpolators, progress: equal ? item.progress : 0, render: equal};
  + var progress = equal ? item.progress : 0;
  + var interpolators = equal ? item.interpolators : this.getInterpolators(item.style, end);
  + return {...item, end, interpolators, progress, render: equal};
  })
  .concat(data
  .filter(dataItem => !itemsByKey[dataItem.key])
  