Add the symfony/asset component

Author: dunglas

composer.json

@@ -10,6 +10,7 @@
     "doctrine/orm": "^2.4.5",
     "doctrine/doctrine-bundle": "^1.6",
     "phpdocumentor/reflection-docblock": "^3.0",
+    "symfony/asset": "^3.0",
     "symfony/expression-language": "^3.0",
     "symfony/security-bundle": "^3.0",
     "symfony/twig-bundle": "^3.0",