ruby-nanoc PKGBUILD now supercedes ruby-nanoc3.

The ruby-nanoc package now `conflicts()` with ruby-nanoc3. Daniel Wallace, from
the aur-general mailing list:

    Just remember there is actually no use for replaces in the aur. That
    directive is only useful in the regular repositories. Provides and
    conflicts is all you actually need for a clean update.

    Replaces is used by pacman to find if there is anything in the repositories
    that replaces something else. Like when we did all the renames of python
    packages.