fix for travis

Author: Hidde Boomsma

.travis.yml

@@ -1,11 +1,13 @@
 language: php
-php:
-  - 7.1
-  - 7.0
-  - 5.6
-  - hhvm
-allow_failures:
-  - php: hhvm
+
+matrix:
+    include:
+        - php: 5.6
+        - php: 7.0
+        - php: 7.1
+        - php: hhvm
+    allow_failures:
+        - php: hhvm
 
 install:
     - composer install