message: remove Heading.withComponent() test
diff: @@ -45,10 +45,3 @@ it('Heading renders fontSize with f* classes using inverse scale', () => {
  expect(render(<Heading fontSize={6} />))
  .toEqual(render(<h1 className='m-0 f0' />))
  })
  -
  -it('Heading.withComponent() returns a tagged component', () => {
  - const Span = Heading.withComponent('span')
  - Span.defaultProps = Heading.defaultProps
  - expect(render(<Span p={1} />))
  - .toEqual(render(<span className='p-1 m-0 f1' />))
  -})
  