message: Get rid of the redundant async keyword
diff: @@ -117,7 +117,7 @@ Errors can be handled using the `.catch` method. Make sure to add `expect.assert
  ```js
  // Testing for async errors using Promise.catch.
  -test('tests error with promises', async () => {
  +test('tests error with promises', () => {
  expect.assertions(1);
  return user.getUserName(2).catch(e =>
  expect(e).toEqual({
  