Unistore when used with stockroom not updating as expected

Suppose I have an initial state like:
```js
data: {}
```

Make an action to return
```js
data: [
{
"userId": 1,
"id": 1,
"title": "sunt aut facere repellat provident occaecati excepturi optio reprehenderit",
"body": "quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto"
},
...
]
```

This will not cause the store to update. In fact no errors are thrown. It just silently fails

Any idea what might be wrong.

This also happens when the initial state is `null` then it is updated with some data and then set back to `null`. The last step does not update the store.

Found https://github.com/developit/stockroom/issues/9 but its for the reverse and it works. `Object` to `null` is not working.

If I get time, I'll make an example repo to better show the issue

#### Update 1:
Looks like unistore/stockroom is internally using `Object.assign` or `push/shift` to set/update the states. This might be the cause of the issue

#### Update 2:
This issue occurs when using unistore with stockroom. Normally it works as expected