Fix build with Tidy
Fix build with Tidy

The Tidy formula was removed from dups: https://github.com/Homebrew/homebrew-dupes/pull/456
It has been replaced by tidy-html5.

Closes #1713.

Signed-off-by: Alan Ivey <ee249fd9166eccef852f50ca0cbb6ff8665afe99@gmail.com>

mkalkbrenner/homebrew-php,dguyon/homebrew-php,ablyler/homebrew-php,TomK/homebrew-php,philcook/homebrew-php