no-javascript-urls for relative URLs

I was using this linter and I noticed that the `no-javascript-urls` rule, when linting relative URLs, on situations such as:

```
<a href="/whatever">Whatever</a>
```

The following error was thrown:

```
TypeError [ERR_INVALID_URL]: Invalid URL
```

I believe it has to do with the `URL()` constructor used requiring the base URL when the URL is relative.