Como faço para modificar o meu composer.json para instalar diretamente no src-dir (Symfony / src)?

{
"name": "acme/example-bundle",
"type": "symfony-bundle",
"license": "MIT",
"require": {
    "php": ">=5.3.2",
    "symfony/framework-bundle": "2.1.*"
},
"suggest": {
    "doctrine/doctrine-bundle": "*"
},
"autoload": {
    "psr-0": { "Acme": "src/" }
},
"target-dir": "../../src/Acme/ExampleBundle"

}