E2E Tests: Intermittent failure in Links tests

[aduth]

Examples:

• https://travis-ci.com/github/WordPress/gutenberg/jobs/310764618
• https://travis-ci.com/github/WordPress/gutenberg/jobs/309771872
• https://travis-ci.com/github/WordPress/gutenberg/jobs/309738798

Error:

FAIL packages/e2e-tests/specs/editor/various/links.test.js (45.265s)

  ● Links › should contain a label when it should open in a new tab
    expect(received).toMatchSnapshot()
    Snapshot name: `Links should contain a label when it should open in a new tab 2`
    - Snapshot
    + Received
      <!-- wp:paragraph -->
    - <p>This is <a href="http://wordpress.org">WordPress</a></p>
    + <p>This is <a href="http://wordpress.org" target="_blank" rel="noreferrer noopener">WordPress</a></p>
      <!-- /wp:paragraph -->
      512 | 		await page.keyboard.press( 'Space' );
      513 | 
    > 514 | 		expect( await getEditedPostContent() ).toMatchSnapshot();
          | 		                                       ^
      515 | 	} );
      516 | } );
      517 | 
      at Object.toMatchSnapshot (specs/editor/various/links.test.js:514:42)
          at runMicrotasks (<anonymous>)