Test against PHP 5.3 through PHP 7 and HHVM

Author: clue

.travis.yml

@@ -1,9 +1,17 @@
 language: php
+
 php:
   - 5.3
+  - 5.4
+  - 5.5
   - 5.6
+  - 7
   - hhvm
+
+sudo: false
+
 install:
-  - composer install --prefer-source --no-interaction
+  - composer install --no-interaction
+
 script:
   - phpunit --coverage-text