language: php
php:
  - "5.5"
  - "5.4"
  - "5.3"
  - "hhvm"
install:
  - composer install

language: php
php:
  - 5.3
  - 5.4
  - 5.5
  - 5.6
  - hhvm
install:
  - composer install

Remove not needed quotes and add PHP 5.6
Remove not needed quotes and add PHP 5.6