Promote hhvm to full support

.travis.yml

@@ -7,10 +7,6 @@ php:
   - 5.5
   - hhvm
 
-matrix:
-  allow_failures:
-    - php: hhvm
-
 before_script:
   - if [ "`phpenv version-name`" != "hhvm" ]; then echo "extension = mongo.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi
   - if [ "`phpenv version-name`" != "hhvm" ]; then echo "extension = amqp.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi