Added a test for hhvm in my travis.yml

Author: paquettg

.travis.yml

@@ -3,6 +3,7 @@ language: php
 php:
   - 5.4
   - 5.5
+  - hhvm
 
 install:
   - composer self-update

README.md

@@ -10,7 +10,7 @@ PHPHtmlParser is a simple, flexible, html parser which allows you to select tags
 Install
 -------
 
-This package can be found on [packagist](https://packagist.org/packages/paquettg/php-html-parser) and is best loaded using [composer](http://getcomposer.org/). It does require php 5.4 or higher, so keep that in consideration. 
+This package can be found on [packagist](https://packagist.org/packages/paquettg/php-html-parser) and is best loaded using [composer](http://getcomposer.org/). We support php 5.4, 5.5, and hhvm 2.3.
 
 Usage
 -----