[PHP] Validate parent's model first, if any (#4659)

* if model has parent, valid() & listInvalidProperties() will check the parents' first

* Run the ./bin/security/php-petstore.sh

samples/client/petstore/php/SwaggerClient-php/test/Model/CapitalizationTest.php

@@ -0,0 +1,133 @@
+<?php
+/**
+ * CapitalizationTest
+ *
+ * PHP version 5
+ *
+ * @category Class
+ * @package  Swagger\Client
+ * @author   Swagger Codegen team
+ * @link     https://github.com/swagger-api/swagger-codegen
+ */
+
+/**
+ * Swagger Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * OpenAPI spec version: 1.0.0
+ * Contact: apiteam@swagger.io
+ * Generated by: https://github.com/swagger-api/swagger-codegen.git
+ *
+ */
+
+/**
+ * NOTE: This class is auto generated by the swagger code generator program.
+ * https://github.com/swagger-api/swagger-codegen
+ * Please update the test case below to test the model.
+ */
+
+namespace Swagger\Client;
+
+/**
+ * CapitalizationTest Class Doc Comment
+ *
+ * @category    Class */
+// * @description Capitalization
+/**
+ * @package     Swagger\Client
+ * @author      Swagger Codegen team
+ * @link        https://github.com/swagger-api/swagger-codegen
+ */
+class CapitalizationTest extends \PHPUnit_Framework_TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass()
+    {
+
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp()
+    {
+
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown()
+    {
+
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass()
+    {
+
+    }
+
+    /**
+     * Test "Capitalization"
+     */
+    public function testCapitalization()
+    {
+
+    }
+
+    /**
+     * Test attribute "small_camel"
+     */
+    public function testPropertySmallCamel()
+    {
+
+    }
+
+    /**
+     * Test attribute "capital_camel"
+     */
+    public function testPropertyCapitalCamel()
+    {
+
+    }
+
+    /**
+     * Test attribute "small_snake"
+     */
+    public function testPropertySmallSnake()
+    {
+
+    }
+
+    /**
+     * Test attribute "capital_snake"
+     */
+    public function testPropertyCapitalSnake()
+    {
+
+    }
+
+    /**
+     * Test attribute "sca_eth_flow_points"
+     */
+    public function testPropertyScaEthFlowPoints()
+    {
+
+    }
+
+    /**
+     * Test attribute "att_name"
+     */
+    public function testPropertyAttName()
+    {
+
+    }
+
+}