drupal-code-sniffer: added drush integration.
drupal-code-sniffer: added drush integration.

Includes some cleanup of the formula.

Extra benefits if a pull request on the "drush" formula is accepted, see
Homebrew/homebrew#25245.

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