Fix travis.yml parsability

Author: hannesvdvreken

.travis.yml

@@ -1,17 +1,16 @@
 language: php
 
-php:
-  - 5.5
-  - 5.6
-  - 7.0
-  - hhvm
-    dist: trusty
-
 matrix:
   fast_finish: true
   allow_failures:
     - php:
       - hhvm
+  include:
+    - php: 5.6
+    - php: 7.0
+    - php: 7.1
+    - php: hhvm
+      dist: trusty
 
 before_install:
   - travis_retry composer self-update