$this->app->bind(\Http\Client\HttpClient::class, function ($app) {
    if ($app->environment('testing')) {
        return new \Swis\Http\Fixture\Client(
            new \Swis\Http\Fixture\ResponseBuilder('/path/to/fixtures')
        );
    } else {
        return \Http\Adapter\Guzzle7\Client::createWithConfig(
            [
                'timeout' => 2,
            ]
        );
    }
});