Updated to reflect new tap names for php in OSX homebrew.

doc/00-intro.md

@@ -112,11 +112,9 @@ Composer is part of the homebrew-php project.
 
 ```sh
 brew update
-brew tap homebrew/homebrew-php
 brew tap homebrew/dupes
-brew tap homebrew/versions
-brew install php55-intl
-brew install homebrew/php/composer
+brew tap homebrew/php
+brew install composer
 ```
 
 ## Installation - Windows