message: add Button test
diff: @@ -3,6 +3,10 @@ import {layout} from 'styled-system'
  import {Button, ButtonPrimary, ButtonDanger, ButtonOutline, ButtonGroup} from '..'
  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)
  function noop() {}
  @@ -11,6 +15,13 @@ describe('Button', () => {
  expect(render(<Button />).type).toEqual('button')
  })
  + it("should have no axe violations", async () => {
  + const {container} = HTMLRender(<Button>Click here</Button>)
  + const results = await axe(container)
  + expect(results).toHaveNoViolations()
  + cleanup()
  + })
  +
  it('has default theme', () => {
  expect(Button).toSetDefaultTheme()
  })
  