Add travis.yml

Author: CHH

.travis.yml

@@ -1,15 +1,10 @@
 language: php
-
 php:
-    - 5.3
-    - 5.4
-    - 5.5
-    - hhvm
-
-matrix:
-    allow_failures:
-        - php: hhvm
-
+    - "5.3"
+    - "5.4"
+    - "5.5"
+    - "5.6"
 
 before_script:
-    - "composer install"
+    - composer self-update
+    - composer install --dev -n