Enabled Payout Cancel API for Unclaimed Payout Item

- PayoutItem supports [Cancel and Unclaimed Payout Item](https://developer.paypal.com/docs/api/#cancel-an-unclaimed-payout-item)
- Updated Unit and Functional Tests Accordingly
- Updated Samples accordingly

tests/PayPal/Test/Api/PayoutItemTest.php

@@ -85,6 +85,26 @@ class PayoutItemTest extends \PHPUnit_Framework_TestCase
         $this->assertNotNull($result);
     }
 
+    /**
+     * @dataProvider mockProvider
+     * @param PayoutItem $obj
+     */
+    public function testCancel($obj, $mockApiContext)
+    {
+        $mockPPRestCall = $this->getMockBuilder('\PayPal\Transport\PayPalRestCall')
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $mockPPRestCall->expects($this->any())
+            ->method('execute')
+            ->will($this->returnValue(
+                PayoutItemDetailsTest::getJson()
+            ));
+
+        $result = $obj->cancel("payoutItemId", $mockApiContext, $mockPPRestCall);
+        $this->assertNotNull($result);
+    }
+
     public function mockProvider()
     {
         $obj = self::getObject();

tests/PayPal/Test/Functional/Api/PayoutsFunctionalTest.php

@@ -65,6 +65,11 @@ class PayoutsFunctionalTest extends \PHPUnit_Framework_TestCase
         $result = $obj->create($params, null, $this->mockPayPalRestCall);
         $this->assertNotNull($result);
         $this->assertEquals(PayoutsFunctionalTest::$batchId, $result->getBatchHeader()->getSenderBatchHeader()->getSenderBatchId());
+        $this->assertEquals('SUCCESS', $result->getBatchHeader()->getBatchStatus());
+        $items = $result->getItems();
+        $this->assertTrue(sizeof($items) > 0);
+        $item = $items[0];
+        $this->assertEquals('UNCLAIMED', $item->getTransactionStatus());
         return $result;
     }
 
@@ -99,4 +104,26 @@ class PayoutsFunctionalTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($item->getPayoutItemFee(), $result->getPayoutItemFee());
     }
 
+    /**
+     * @depends testCreate
+     * @param $payoutBatch PayoutBatch
+     * @return PayoutBatch
+     */
+    public function testCancel($payoutBatch)
+    {
+        $items = $payoutBatch->getItems();
+        $item = $items[0];
+        if ($item->getTransactionStatus() != 'UNCLAIMED') {
+            $this->markTestSkipped('Transaction status needs to be Unclaimed for this test ');
+            return;
+        }
+        $result = PayoutItem::cancel($item->getPayoutItemId(), null, $this->mockPayPalRestCall);
+        $this->assertNotNull($result);
+        $this->assertEquals($item->getPayoutItemId(), $result->getPayoutItemId());
+        $this->assertEquals($item->getPayoutBatchId(), $result->getPayoutBatchId());
+        $this->assertEquals($item->getTransactionId(), $result->getTransactionId());
+        $this->assertEquals($item->getPayoutItemFee(), $result->getPayoutItemFee());
+        $this->assertEquals('RETURNED', $result->getTransactionStatus());
+    }
+
 }

tests/PayPal/Test/Functional/resources/PayoutsFunctionalTest/testCancel.json

@@ -0,0 +1,76 @@
+{
+  "description":"User initiates cancel on unlcaimed payouts item.",
+  "title":"Cancel item sample",
+  "runnable":true,
+  "operationId":"payouts.item.cancel",
+  "user":{
+    "scopes":[
+
+    ]
+  },
+  "credentials":{
+    "oauth":{
+      "path":"/v1/oauth/token",
+      "clientId":"",
+      "clientSecret":""
+    }
+  },
+  "request":{
+    "path":"v1/payments/payouts-item/452345/cancel",
+    "method":"POST",
+    "headers":{
+      "Content-Type":"application/json",
+      "Content-Encoding":"gzip"
+    },
+    "body":{
+
+    }
+  },
+  "response":{
+    "status":"200 OK",
+    "headers":{
+      "Content-Type":"application/json",
+      "Content-Encoding":"gzip"
+    },
+    "body":{
+      "payout_item_id":"VHBFGN95AWV82",
+      "transaction_id":"0728664497487461D",
+      "transaction_status":"RETURNED",
+      "payout_item_fee":{
+        "currency":"USD",
+        "value":"0.02"
+      },
+      "payout_batch_id":"CDZEC5MJ8R5HY",
+      "sender_batch_id":"2014021801",
+      "payout_item":{
+        "recipient_type":"EMAIL",
+        "amount":{
+          "value":"1.00",
+          "currency":"USD"
+        },
+        "note":"Thanks for your patronage!",
+        "receiver":"anybody01@gmail.com",
+        "payouts_item_id":"1421342",
+        "sender_item_id":"14Feb_234"
+      },
+      "time_processed":"2014-01-27T10:17:41Z",
+      "errors":{
+        "name":"RECEIVER_UNREGISTERED",
+        "message":"Receiver is unregistered",
+        "information_link": "https://developer.paypal.com/webapps/developer/docs/api/#RECEIVER_UNREGISTERED"
+      },
+      "links":[
+        {
+          "rel":"self",
+          "href":"https://api.sandbox.paypal.com/v1/payments/payouts-item/1421342",
+          "method":"GET"
+        },
+        {
+          "rel":"batch",
+          "href":"https://api.sandbox.paypal.com/v1/payments/payouts/20140724",
+          "method":"GET"
+        }
+      ]
+    }
+  }
+}

tests/PayPal/Test/Functional/resources/PayoutsFunctionalTest/testCreate.json

@@ -68,7 +68,7 @@
         			{
             			"payout_item_id": "VHBFGN95AWV82",
             			"transaction_id": "0728664497487461D",
-            			"transaction_status": "SUCCESS",
+            			"transaction_status": "UNCLAIMED",
             			"payout_item_fee": {
                 			"currency": "USD",
                 			"value": "0.02"