Init multi payment endpoint and samples added

samples/init_multi_payment.php

@@ -0,0 +1,35 @@
+<?php
+
+use Craftgate\Model\Currency;
+use Craftgate\Model\PaymentGroup;
+use Craftgate\Model\PaymentPhase;
+use Craftgate\Util\Guid;
+
+require_once('config/sample_config.php');
+
+$request = array(
+    'price' => 100,
+    'paidPrice' => 100,
+    'callbackUrl' => 'callbackUrl',
+    'currency' => Currency::TL,
+    'conversationId' => '456d1297-908e-4bd6-a13b-4be31a6e47d5',
+    'externalId' => Guid::generate(),
+    'paymentGroup' => PaymentGroup::PRODUCT,
+    'paymentPhase' => PaymentPhase::AUTH,
+    'items' => array(
+        array(
+            'name' => 'Item 1',
+            'externalId' => '38983903',
+            'price' => 60,
+        ),
+        array(
+            'name' => 'Item 2',
+            'externalId' => '92983294',
+            'price' => 40,
+        )
+    )
+);
+
+$response = SampleConfig::craftgate()->payment()->initMultiPayment($request);
+
+print_r($response);

src/Adapter/PaymentAdapter.php

@@ -271,6 +271,12 @@ public function retrieveActiveBanks()
         return $this->httpGet($path);
     }
 
+    public function initMultiPayment(array $request)
+    {
+        $path = "/payment/v1/multi-payments/init";
+        return $this->httpPost($path, $request);
+    }
+
     public function retrieveMultiPayment($token)
     {
         $path = "/payment/v1/multi-payments/" . $token;