Let HHVM fail /shrug

.travis.yml

@@ -16,9 +16,11 @@ matrix:
     - php: 7.2
     - php: hhvm
       dist: trusty
+  allow_failures:
+    - php: hhvm
 
 script:
- - '[[ "$TRAVIS_PHP_VERSION" = 5.2* ]] && phpunit || vendor/bin/phpunit --verbose'
+  - '[[ "$TRAVIS_PHP_VERSION" = 5.2* ]] && phpunit || vendor/bin/phpunit --verbose'
 
 install:
- - '[[ "$TRAVIS_PHP_VERSION" = 5.2* ]] || composer install'
+  - '[[ "$TRAVIS_PHP_VERSION" = 5.2* ]] || composer install'