Behat and Symfony2

behat.yml

default:
  extensions:
    Behat\Symfony2Extension: ~

composer.json

{
    "require-dev": {
        "sensio/generator-bundle": "~2.3",
        "hautelook/alice-bundle": "0.2.*",
        "behat/behat": "~3.0",
        "behat/symfony2-extension": "~2.0",
        "behat/mink-extension": "~2.0",
        "behat/mink-selenium2-driver": "~1.2",
        "behat/mink": "~1.6"
    }
}