Updated .travis.yml for PHP 7.1.

Author: Harrison Heck

.travis.yml

@@ -1,22 +1,13 @@
 language: php
 
 php:
-  - 5.4
-  - 5.5
-  - 5.6
-  - 7.0
-  - hhvm
+  - 7.1
 
 before_install:
   - travis_retry composer self-update
 install:
   - travis_retry composer install --no-interaction --prefer-source --dev
 
 script:
-  - bin/phpunit --verbose
+  - vendor/bin/phpunit --verbose
 
-matrix:
-  allow_failures:
-    - php: hhvm
-    - php: 7.0
-  fast_finish: true