Merge pull request #2868 from zeke/master

update homebrew instructions

doc/00-intro.md

@@ -95,13 +95,13 @@ Then, just run `composer` in order to run Composer instead of `php composer.phar
 
 Composer is part of the homebrew-php project.
 
-1. Tap the homebrew-php repository into your brew installation if you haven't done
+```sh
-   so yet: `brew tap josegonzalez/homebrew-php`
+brew update
-2. Run `brew install josegonzalez/php/composer`.
+brew tap josegonzalez/homebrew-php
-3. Use Composer with the `composer` command.
+brew tap homebrew/versions
-
+brew install php55-intl
-> **Note:** If you receive an error saying PHP53 or higher is missing use this command to install php 
+brew install josegonzalez/php/composer
-> `brew install php53-intl`
+```
 
 ## Installation - Windows