title: React-testing-library and <Link> Element type is invalid: expected a string or a class/function but got: undefined
body: <p>I'm using <code>react-testing-library</code> to test a simple component which has a nested react-router-dom's <code>&lt;Link&gt;</code> inside of it and I am getting this error:</p>
  <pre><code> Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.
  </code></pre>