Migrations logic and custom configs

My migrations are failing with Error: Cannot load database configuration. I have my config setup like this... config.ini, development.ini & production.ini. Within config.ini I have a variable I can set to either "debelopment" or "production". Then in Bootstrap.php I have the following;

protected function config()
{
    $config = new \Phalcon\Config\Adapter\Ini(APP_PATH . '/app/common/config/config.ini');
    $this->_di->set('config', $config);
    if($this->config->app->env == 'development'){
        $dev = new \Phalcon\Config\Adapter\Ini(APP_PATH . '/app/common/config/development.ini');
        $config->merge($dev);
    }else{
        $prod = new \Phalcon\Config\Adapter\Ini(APP_PATH . '/app/common/config/production.ini');
        $config->merge($prod);
    }
    $this->_config = $config;
}

This is probably why migrations are failing. My development database and production database have different credentials. What ligic does devtools migrations use to find the database configurations?