more tests on travis

Author: gossi

.travis.yml

@@ -1,13 +1,11 @@
 language: php
 
 php:
-#  - 5.4
-# disabled because of symfony 3
+  - 5.4
   - 5.5
   - 5.6
-#  - hhvm
-# disabled hhvm because of a bug in 3.2.0 which is resolved in 3.3.0
-# see: https://github.com/facebook/hhvm/issues/3932
+  - 7.0
+  - hhvm
 
 install:
   - composer install