Updated Payment APIs

- Updated SDK Models to latest Payment APIs
- Updated Unit Tests

tests/PayPal/Test/Api/MeasurementTest.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace PayPal\Test\Api;
+
+use PayPal\Common\PayPalModel;
+use PayPal\Api\Measurement;
+
+/**
+ * Class Measurement
+ *
+ * @package PayPal\Test\Api
+ */
+class MeasurementTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * Gets Json String of Object Measurement
+     * @return string
+     */
+    public static function getJson()
+    {
+        return '{"value":"TestSample","unit":"TestSample"}';
+    }
+
+    /**
+     * Gets Object Instance with Json data filled in
+     * @return Measurement
+     */
+    public static function getObject()
+    {
+        return new Measurement(self::getJson());
+    }
+
+
+    /**
+     * Tests for Serialization and Deserialization Issues
+     * @return Measurement
+     */
+    public function testSerializationDeserialization()
+    {
+        $obj = new Measurement(self::getJson());
+        $this->assertNotNull($obj);
+        $this->assertNotNull($obj->getValue());
+        $this->assertNotNull($obj->getUnit());
+        $this->assertEquals(self::getJson(), $obj->toJson());
+        return $obj;
+    }
+
+    /**
+     * @depends testSerializationDeserialization
+     * @param Measurement $obj
+     */
+    public function testGetters($obj)
+    {
+        $this->assertEquals($obj->getValue(), "TestSample");
+        $this->assertEquals($obj->getUnit(), "TestSample");
+    }
+
+}