title: Trouble adding react-testing-library to a project - TypeError: Cannot read property 'then' of undefined
body: <p>Having trouble adding react-testing-library to a project.</p>
  
  <p>Project is currently using these versions</p>
  
  <pre><code>"react": "16.10.2",
  "react-dom": "16.10.2"
  "jest": "24.9.0"
  </code></pre>
  
  <p>and I'm adding these versions for react-testing-library</p>
  
  <pre><code>"@testing-library/dom": "^6.10.0",
  "@testing-library/jest-dom": "^4.2.2",
  "@testing-library/react": "^9.3.1",
  "@testing-library/user-event": "^7.1.2"
  </code></pre>
  
  <p>Running a basic test like this</p>
  
  <pre><code>import React from 'react';
  import { render } from '@testing-library/react';
  import '@testing-library/jest-dom/extend-expect';
  
  test('react-testing-library hello world', () =&gt; {
      const {getByText} = render(
          &lt;div&gt;Hello&lt;/div&gt;
      );
      expect(getByText('Hello')).toBeInTheDocument();
  });
  </code></pre>
  
  <p>Gets this error for 'render()'</p>
  
  <pre><code>TypeError: Cannot read property 'current' of undefined
  </code></pre>
  
  <p>Any ideas? Tried updating react and react-dom to latest and still got the same</p>