[PHP][Symfony] Enhancements (#6615)

* Removed commented code

* Input validation is now supported as strict JSON validation

* [PHP][Symfony] Improve the implementation
Closes #6614

* Generated code is tested to assure it compiles and updated README to dynamically load dependencies via composer

* Updated shell script because shippable tests were failing

samples/server/petstore/php-symfony/SymfonyBundle-php/Api/ApiServer.php

@@ -0,0 +1,80 @@
+<?php
+/**
+ * ApiServer
+ *
+ * PHP version 5
+ *
+ * @category Class
+ * @package  Swagger\Server\Api
+ * @author   Swagger Codegen team
+ * @link     https://github.com/swagger-api/swagger-codegen
+ */
+
+/**
+ * Swagger Petstore
+ *
+ * This is a sample server Petstore server.  You can find out more about Swagger at [http://swagger.io](http://swagger.io) or on [irc.freenode.net, #swagger](http://swagger.io/irc/).  For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * 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
+ * Do not edit the class manually.
+ */
+
+namespace Swagger\Server\Api;
+
+/**
+ * ApiServer Class Doc Comment
+ *
+ * PHP version 5
+ *
+ * @category Class
+ * @package  Swagger\Server\Api
+ * @author   Swagger Codegen team
+ * @link     https://github.com/swagger-api/swagger-codegen
+ */
+class ApiServer
+{
+
+    /**
+     * @var array
+     */
+    private $apis = array();
+
+    /**
+     * Adds an API handler to the server.
+     *
+     * @param string $api An API name of the handle
+     * @param mixed $handler A handler to set for the given API
+     */
+    public function addApiHandler($api, $handler)
+    {
+        if (isset($this->apis[$api])) {
+            throw new \InvalidArgumentException('API has already a handler: '.$api);
+        }
+
+        $this->apis[$api] = $handler;
+    }
+
+    /**
+     * Returns an API handler.
+     *
+     * @param string $api An API name of the handle
+     * @return mixed Returns a handler
+     * @throws \InvalidArgumentException When no such handler exists
+     */
+    public function getApiHandler($api)
+    {
+        if (!isset($this->apis[$api])) {
+            throw new \InvalidArgumentException('No handler for '.$api.' implemented.');
+        }
+
+        return $this->apis[$api];
+    }
+}