Wrap render calls with act() for better Hooks integration

[thymikee]

Hooks work fine even without it, but you'll likely need to add asynchrony to your code. With act() you'll be able to achieve the same results in synchronous manner.

See: https://reactjs.org/blog/2019/02/06/react-v16.8.0.html#testing-hooks

[ccfz]

It would be great if update is also be wrapped with act().

[Esemesek]

@ccfz Would appreciate a PR with an example test for this functionality.