protected function getServices($config)
    {
        $services       = array();
        $travisServices = isset($config['services']) && is_array($config['services']) ? $config['services'] : array();

        foreach ($travisServices as $service) {
            if (isset($this->servicesMapping[$service])) {
                $services[] = new Service(
                    $service,
                    $this->servicesMapping[$service]['repository'],
                    $this->servicesMapping[$service]['tag'],
                    $this->servicesMapping[$service]['config']
                );
            }
        }

        return $services;
    }