message: un-comment LAYOUT system props check
diff: @@ -2,7 +2,7 @@ import React from 'react'
  import Box from '../Box'
  import theme from '../theme'
  import {render} from '../utils/testing'
  -import {COMMON} from '../system-props'
  +import {COMMON, LAYOUT} from '../system-props'
  describe('Box', () => {
  it('is a system component', () => {
  @@ -11,8 +11,7 @@ describe('Box', () => {
  it('implements layout system props', () => {
  expect(Box).toImplementSystemProps(COMMON)
  - // FIXME
  - // expect(Box).toImplementSystemProps(LAYOUT)
  + expect(Box).toImplementSystemProps(LAYOUT)
  })
  it('renders without any props', () => {
  