message: Remove redundant system props
diff: import PropTypes from 'prop-types'
  import styled from 'styled-components'
  import classnames from 'classnames'
  -import {LAYOUT, get} from './constants'
  +import {get} from './constants'
  import theme from './theme'
  import elementType from './utils/elementType'
  import Box from './Box'
  @@ -15,8 +15,6 @@ const Popover = styled(Box).attrs(({className, caret}) => {
  position: ${props => (props.relative ? 'relative' : 'absolute')};
  z-index: 100;
  display: ${props => (props.open ? 'block' : 'none')};
  -
  - ${LAYOUT};
  `
  Popover.Content = styled(BorderBox)`
  @@ -224,8 +222,7 @@ Popover.propTypes = {
  open: PropTypes.bool,
  relative: PropTypes.bool,
  theme: PropTypes.object,
  - ...Box.propTypes,
  - ...LAYOUT.propTYpes
  + ...Box.propTypes
  }
  Popover.Content.defaultProps = {
  