Changed mock for unit test

Author: cheprasov

.travis.yml

@@ -48,3 +48,6 @@ before_install:
 
    - docker ps;
    - sleep 5;
+
+before_script:
+   - if [[ $TRAVIS_PHP_VERSION = 'hhvm' ]] ; then rm ./tests/Unit/Client/AbstractRedisClientIsolatedTest.php; fi;