Fix `scripts` field usage in package.json

You where misusing the `scripts` field in package.json.

As I commented on your code:

* [first comment](https://github.com/substack/testling/commit/c0a2bb5e5fd93ec16c42cc96601f9d8b6a57cfdd#commitcomment-3485550)
* [second comment](https://github.com/substack/testling/commit/c0a2bb5e5fd93ec16c42cc96601f9d8b6a57cfdd#commitcomment-3485552)

You need to use `expanded.script` and as `unglog` is async, we need to update the HTML after we got the right scripts.
I made a quickfix so I can update the html accordingly and hurra, the `scripts` fields works!