update travis

Author: gossi

.travis.yml

@@ -1,18 +1,18 @@
 language: php
+
 dist: trusty
 
 php:
-  - 5.4
-  - 5.5
   - 5.6
   - 7.0
+  - 7.1
   - hhvm
 
 install:
   - composer install
 
 script:
-  - phpunit --coverage-clover=coverage.clover
+  - vendor/bin/phpunit --coverage-clover=coverage.clover
 
 after_script:
   - wget https://scrutinizer-ci.com/ocular.phar