{

  "repositories": [
    {
        "type": "vcs",
        "url": "https://github.com/mozilla-l10n/phpclass-json"
    }
],
    "require": {
        "guzzlehttp/guzzle": "~6.0",
        "twig/twig": "^1.0",
        "components/jquery": "~2",
        "mozillal10n/json": "~0.1"
    },

    "require-dev": {
        "atoum/atoum" : "~2.0",
        "symfony/var-dumper": "~2.6",
        "fabpot/php-cs-fixer": "~1.4"
    },

    "autoload": {
        "psr-0": {"Nightly": "app/classes/"},
        "files": ["app/helpers/debug.php"]
    }
}

{

  "repositories": [
    {
        "type": "vcs",
        "url": "https://github.com/mozilla-l10n/phpclass-json"
    }
],
    "require": {
        "guzzlehttp/guzzle": "~5.0",
        "twig/twig": "^1.0",
        "components/jquery": "~2",
        "mozillal10n/json": "~0.1"
    },

    "require-dev": {
        "atoum/atoum" : "~2.0",
        "symfony/var-dumper": "~2.6",
        "fabpot/php-cs-fixer": "~1.4"
    },

    "autoload": {
        "psr-0": {"Nightly": "app/classes/"},
        "files": ["app/helpers/debug.php"]
    }
}

Update guzzle version for PHP 5.4
Update guzzle version for PHP 5.4