Error with <Modal>

When clicking the + button on `/reviews`:

```
index.js:2177 Material-UI: The modal content node does not accept focus.
For the benefit of assistive technologies, the tabIndex of the node is being set to "-1". 
```

![image](https://user-images.githubusercontent.com/251288/113786706-b3151280-9707-11eb-9e14-22ba96a2ba03.png)
