with the use of below blog article a am able to configure braintree payment gateway lib on may server manually .
http://www.loneshooter.com/zend-framework-2-how-to-use-facebook-php-sdk/
1) Here i need to add lib reference in autoload_classmap.php like below.
<?php
return array(
'Braintree' => 'vendor/< path to Braintree >/Braintree.php',
);
2) In function getAutoloaderConfig of Module.php file add ClassMapAutoloader section if it doesn’t exist in order to load configurations from autoload_classmap.php file. The function should look as it follows:
public function getAutoloaderConfig()
{
return array(
'Zend\Loader\ClassMapAutoloader' => array(
__DIR__ . '/autoload_classmap.php',
),
'Zend\Loader\StandardAutoloader' => array(
'namespaces' => array(
__NAMESPACE__ => __DIR__ . '/src/' . __NAMESPACE__,
),
),
);
}
3) After the changes i can use the Braintree library in your controller:
$Braintree = new \Braintree\Configuration();
$Braintree::merchantId('your_merchant_id');
$Braintree::publicKey('your_public_key');
$Braintree::privateKey('your_private_key');