Declare license and author attribution in package.json

Hi! Thanks for your great work!
Would you mind adding the license and author attribution info to package.json? e.g.

```text
  "author": "Ryan LeFevre (https://github.com/meltingice)",
  "license": "MIT",
  "private": false,
```

That way, npm and license management tools can detect it.