Travis improvements

Author: GrahamCampbell

.travis.yml

@@ -4,9 +4,11 @@ php:
   - 5.4
   - 5.5
   - 5.6
+  - hhvm
 
 before_script:
-  - curl -s http://getcomposer.org/installer | php
-  - php composer.phar install --dev
+  - travis_retry composer self-update
+  - travis_retry composer install --no-interaction --prefer-source --dev
 
-script: phpunit
+script:
+  - vendor/bin/phpunit --verbose