Prefer project-root to project-roots

[manuel-uberti]

Hi,

first of all thanks for this great package.

May I suggest to use project-root instead of project-roots in rg-project-root? project-roots is deprecated.

Thank you!

[dajva]

Thanks for the kind words and the suggestion.

This change is too new to get from emacs internally since this package supports emacs-25.1.
It's possible to have it as a requirement of course and get a newer version from elpa but since the project system used is optional I don't really want to depend on any of them explicitly.

I'll keep this open and see what to do. Maybe just check if project-root is available and us it if it is.

[manuel-uberti]

Totally understand your point. Feel free to close this whenever you like.

[hmelman]

Maybe just check if project-root is available and us it if it is.

Now that Emacs 28 is out, perhaps its time to do this.