Adding additional depedencies which aren't installing for some users - https://github.com/jonnnnyw/php-phantomjs/issues/17

composer.json

@@ -14,9 +14,11 @@
     "minimum-stability": "stable",
     "require": {
         "php": ">=5.3.0",
-        "symfony/config": "2.5.0",
-        "symfony/dependency-injection": "2.5.0",
-        "twig/twig": "1.16",
+        "symfony/config": "~2.5",
+        "symfony/dependency-injection": "~2.5",
+        "symfony/filesystem": "~2.5",
+        "symfony/yaml": "~2.5",
+        "twig/twig": "~1.16",
         "jakoch/phantomjs-installer": "1.9.7"
     },
     "require-dev": {