useReplicant doesn't support passing a function to setReplicant

An example with `useState` and `useReplicant`:
```js
const [data, setData] = React.useState(0);
setData(previousData => previousData + 1);

const [replicant, setReplicant] = useReplicant(0);
setReplicant(previousData => previousData + 1); // this is not supported!
```
Would be great if that was supported, because old values could be captured when using `useEffect` for example.