Fix getPaymentMethods endpoint

Author: m1k3lm

src/Client.php

@@ -145,7 +145,10 @@ public function getMerchantPaymentMethods($merchant)
 
     public function getPaymentMethods($uri, $options = array())
     {
-        $this->initCurl($this->_endpoint . '/merchants/');
+        if (!preg_match('!^https?://!', $uri)) {
+            $uri = $this->_endpoint . '/orders/' . $uri;
+        }
+        $this->initCurl($uri . '/payment_methods' . (count($options) > 0 ? '?' . http_build_query($options) : ''));
         curl_setopt($this->ch, CURLOPT_CUSTOMREQUEST, 'GET');
         curl_setopt($this->ch, CURLOPT_HTTPHEADER, array('Accept: application/json'));
         $this->sendRequest();