message: don't call withSystemProps() on CaretBox
diff: import React from 'react'
  import Box from './Box'
  import Caret from './Caret'
  -import {withSystemProps} from './system-props'
  function CaretBox(props) {
  // don't destructure these, just grab them
  const {bg, borderColor} = props
  const {caret, children, ...rest} = props
  - const caretProps = {
  - location: caret,
  - borderColor,
  - bg
  - }
  -
  + const caretProps = {bg, borderColor, location: caret}
  return (
  <Box {...rest}>
  {children}
  @@ -31,4 +25,4 @@ CaretBox.defaultProps = {
  position: 'relative'
  }
  -export default withSystemProps(CaretBox, ['color'])
  +export default CaretBox
  