message: make position system prop responsive
diff: @@ -13,10 +13,12 @@ export const margin = createResponsiveMapper(marginProps)
  export const padding = createResponsiveMapper(paddingProps)
  export const spacing = composeWithPropTypes(margin, padding)
  -export const position = createClassMapper(
  - 'position',
  - value => `position-${value}`,
  - PropTypes.oneOf(['relative', 'absolute', 'fixed'])
  +export const position = createResponsiveMapper(
  + ['position'],
  + ({value}) => `position-${value}`,
  + {
  + position: PropTypes.oneOf(['relative', 'absolute', 'fixed'])
  + }
  )
  export const flex = createResponsiveMapper(
  