src/LumenServiceProvider.php
protected function version()
    {
        $version = explode('(', $this->app->version());
        if (isset($version[1])) {
            return substr($version[1], 0, 3);
        }        
        return null;
    }
protected function version()
    {
        $version = explode('(', $this->app->version());
        if (isset($version[1])) {
            return substr($version[1], 0, 3);
        }        
        return null;
    }
Get Lumen version