message: update StyledOcticon test
diff: @@ -3,12 +3,23 @@ import {X} from '@primer/octicons-react'
  import StyledOcticon from '../StyledOcticon'
  import {render} from '../utils/testing'
  import {COMMON} from '../constants'
  +import {render as HTMLRender, cleanup} from "@testing-library/react";
  +import {axe, toHaveNoViolations} from 'jest-axe'
  +import 'babel-polyfill'
  +expect.extend(toHaveNoViolations)
  describe('StyledOcticon', () => {
  it('implements system props', () => {
  expect(StyledOcticon).toImplementSystemProps(COMMON)
  })
  + it('should have no axe violations', async () => {
  + const {container} = HTMLRender(<StyledOcticon icon={X} />)
  + const results = await axe(container)
  + expect(results).toHaveNoViolations()
  + cleanup()
  + })
  +
  it('matches the snapshot', () => {
  expect(render(<StyledOcticon icon={X} />)).toMatchSnapshot()
  })
  