deloreanjs/delorean — pull request #40 by rkusa (2014-10-23 10:21:29+00:00)
Title: fix scheme properties that are set to null

delorean throws if having a scheme property that defaults to `null`, e.g.,

```js
Flux.createStore({
scheme: {
prop: null
}
})
```

because `typeof null === 'object'`.

This PR fixes this issue by checking if `definition` is set before checking if its an object.