Fix tap directory location

Since https://github.com/Homebrew/homebrew/pull/28203 the location for
homebrew taps has changed to
/usr/local/Homebrew/Taps/username/homebrew-tapname. This change both removes
the slash to dash conversation, and also adds the homebrew- prefix to the
tapname.
Merge pull request #27 from mivok/homebrew_tap_fix

Fix tap directory location