Add some tests, refactor render() to return a promise, use expand for options

This can be rejected and will simply fold into a later commit introducing new functionality.

* Add a unit test for FileInfo
* Refactor FileInfo#render to return a promise
* Prompt users with multiple options via `expand` instead of a confirmation.

![](https://api.monosnap.com/image/download?id=2ZHY9oacHwODpYpGJaONLWU04BoZMJ)