title: Material UI Select - object as value fails
body: <p>in my app I'm using Material UI an React. I created a Select dropdown in order to change the displayed values. So when I change the selection, the data on the page should be updated. Unfortunately, I can't add my object to the value property of the MenuItem. In CodeSandbox it is working with an underlined value, but not in my local environment.</p>
  <p>Code: <a href="https://codesandbox.io/s/select-exmpl-iosfg" rel="nofollow noreferrer">https://codesandbox.io/s/select-exmpl-iosfg</a></p>
  <p>Local error:
  <a href="https://i.stack.imgur.com/GbxHO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GbxHO.png" alt="enter image description here" /></a></p>