Adding Delivery Confirmation functionality to PackageServiceOptions f…

…or domestic shipments.

Was told by UPS support that:

"Please try to request a Adult Signature under PackageServiceOptions and not ShipmentServiceOptions. Usually, ShipmentServiceOptions is for International packages. "

When originally using Delivery Confirmation on ShipmentServiceOptions, I was receiving the error, which is now resolved with the committed changes.

"The requested accessory option is unavailable between the selected locations."

An example of code to utilize this on a domestic shipment is:

```
    $deliveryConfirmation = new \Ups\Entity\DeliveryConfirmation;
    $deliveryConfirmation->setDcisType(2);

    $packageServiceOptions = new \Ups\Entity\PackageServiceOptions();
    $packageServiceOptions->setDeliveryConfirmation($deliveryConfirmation);
    $package->setPackageServiceOptions($packageServiceOptions);
```

src/Entity/PackageServiceOptions.php

@@ -42,6 +42,11 @@ class PackageServiceOptions implements NodeInterface
      */
     private $holdForPickup;
 
+    /**
+     * @var DeliveryConfirmation
+     */
+    private $deliveryConfirmation;
+
     /**
      * @param null $parameters
      */
@@ -60,6 +65,9 @@ public function __construct($parameters = null)
             if (isset($parameters->HoldForPickup)) {
                 $this->setHoldForPickup($parameters->HoldForPickup);
             }
+            if (isset($parameters->DeliveryConfirmation)) {
+                $this->setDeliveryConfirmation($parameters->DeliveryConfirmation);
+            }
         }
     }
 
@@ -87,6 +95,9 @@ public function toNode(DOMDocument $document = null)
         if ($this->getHazMatPackageInformation() !== null) {
             $node->appendChild($this->getHazMatPackageInformation()->toNode($document));
         }
+        if (isset($this->deliveryConfirmation)) {
+            $node->appendChild($this->deliveryConfirmation->toNode($document));
+        }
 
         return $node;
     }
@@ -194,4 +205,22 @@ public function setHazMatPackageInformation($hazMatPackageInformation)
     {
         $this->hazMatPackageInformation = $hazMatPackageInformation;
     }
+
+    /**
+     * @param DeliveryConfirmation $deliveryConfirmation
+     * @return ShipmentServiceOptions
+     */
+    public function setDeliveryConfirmation(DeliveryConfirmation $deliveryConfirmation)
+    {
+        $this->deliveryConfirmation = $deliveryConfirmation;
+        return $this;
+    }
+
+    /**
+     * @return DeliveryConfirmation|null
+     */
+    public function getDeliveryConfirmation()
+    {
+        return $this->deliveryConfirmation;
+    }
 }