update travis.yml

Author: anlutro

.travis.yml

@@ -4,8 +4,17 @@ php:
   - 5.4
   - 5.5
   - 5.6
+  - 7.0
   - hhvm
+  - hhvm-nightly
+
+matrix:
+  allow_failures:
+    - php: 7.0
+    - php: hhvm-nightly
 
 install: composer install --dev --prefer-dist
 
 script: phpunit
+
+sudo: false