composer.json for themes running Timber (working as of February 19th 2015)

gistfile1.json

{
    "require": {
        "composer/installers": "~1",
        "jarednova/timber": "dev-master"
    },
    "repositories": [
        {
            "type" : "package",
            "package" : {
                "name" : "jarednova/php-router",
                "version" : "1.0.1",
                "dist" : {
                    "url" : "https://github.com/jarednova/PHP-Router/archive/fix_psr_0.zip",
                    "type" : "zip"
                },
                "autoload": {
                    "psr-0": {
                        "PHPRouter": "src/"
                    }
                }
            }
        }
    ],
    "extra": {
        "installer-paths": {
          "vendor/timber": ["jarednova/timber"]
        }
      },
      "autoload": {
        "classmap": [ "vendor/timber" ]
    }
}