Added docs of how to debug (#315)

* Added debug options

* Added docs

* cs

README.md

@@ -125,20 +125,22 @@ Go to http://bin.mailgun.net. The Postbin will generate a special URL. Save that
 
 **Step 2 - Instantiate the Mailgun client using Postbin.**  
 
-*Tip: The bin id will be the URL part after bin.mailgun.net. It will be random generated letters and numbers. For example, the bin id in this URL, http://bin.mailgun.net/aecf68de, is "aecf68de".*
+*Tip: The bin id will be the URL part after bin.mailgun.net. It will be random generated letters and numbers. 
+For example, the bin id in this URL, http://bin.mailgun.net/aecf68de, is "aecf68de".*
 
 ```php
-# First, instantiate the SDK with your API credentials and define your domain. 
-$mg = new Mailgun('key-example', null, 'bin.mailgun.net');
-$mg->setApiVersion('aecf68de');
-$mg->setSslEnabled(false);
-$domain = 'example.com';
+$configurator = new HttpClientConfigurator();
+$configurator->setEndpoint('http://bin.mailgun.net/aecf68de');
+$configurator->setDebug(true);
+$mg = Mailgun::configure($configurator);
 
 # Now, compose and send your message.
-$mg->sendMessage($domain, array('from'    => 'bob@example.com', 
+$mg->sendMessage('example.com', [
+  'from'    => 'bob@example.com', 
   'to'      => 'sally@example.com', 
   'subject' => 'The PHP SDK is awesome!', 
-                                'text'    => 'It is so simple to send a message.'));
+  'text'    => 'It is so simple to send a message.']
+);
 ```
 ### Additional Info
 

src/Mailgun/HttpClient/Plugin/ReplaceUriPlugin.php

@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * Copyright (C) 2013-2016 Mailgun
+ *
+ * This software may be modified and distributed under the terms
+ * of the MIT license. See the LICENSE file for details.
+ */
+
+namespace Mailgun\HttpClient\Plugin;
+
+use Http\Client\Common\Plugin;
+use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\UriInterface;
+
+/**
+ * Replaces a URI with a new one. Good for debugging.
+ *
+ * @author Tobias Nyholm <tobias.nyholm@gmail.com>
+ */
+final class ReplaceUriPlugin implements Plugin
+{
+    /**
+     * @var UriInterface
+     */
+    private $uri;
+
+    /**
+     * @param UriInterface $uri
+     */
+    public function __construct(UriInterface $uri)
+    {
+        $this->uri = $uri;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function handleRequest(RequestInterface $request, callable $next, callable $first)
+    {
+        $request = $request->withUri($this->uri);
+
+        return $next($request);
+    }
+}

src/Mailgun/HttpClientConfigurator.php

@@ -16,6 +16,7 @@ use Http\Discovery\UriFactoryDiscovery;
 use Http\Message\UriFactory;
 use Http\Client\Common\Plugin;
 use Mailgun\HttpClient\Plugin\History;
+use Mailgun\HttpClient\Plugin\ReplaceUriPlugin;
 
 /**
  * Configure a HTTP client.
@@ -29,6 +30,13 @@ final class HttpClientConfigurator
      */
     private $endpoint = 'https://api.mailgun.net';
 
+    /**
+     * If debug is true we will send all the request to the endpoint without appending any path.
+     *
+     * @var bool
+     */
+    private $debug = false;
+
     /**
      * @var string
      */
@@ -60,7 +68,7 @@ final class HttpClientConfigurator
     public function createConfiguredClient()
     {
         $plugins = [
-            new Plugin\AddHostPlugin($this->getUriFactory()->createUri($this->getEndpoint())),
+            new Plugin\AddHostPlugin($this->getUriFactory()->createUri($this->endpoint)),
             new Plugin\HeaderDefaultsPlugin([
                 'User-Agent' => 'mailgun-sdk-php/v2 (https://github.com/mailgun/mailgun-php)',
                 'Authorization' => 'Basic '.base64_encode(sprintf('api:%s', $this->getApiKey())),
@@ -68,15 +76,23 @@ final class HttpClientConfigurator
             new Plugin\HistoryPlugin($this->responseHistory),
         ];
 
+        if ($this->debug) {
+            $plugins[] = new ReplaceUriPlugin($this->getUriFactory()->createUri($this->endpoint));
+        }
+
         return new PluginClient($this->getHttpClient(), $plugins);
     }
 
     /**
-     * @return string
+     * @param bool $debug
+     *
+     * @return HttpClientConfigurator
      */
-    private function getEndpoint()
+    public function setDebug($debug)
     {
-        return $this->endpoint;
+        $this->debug = $debug;
+
+        return $this;
     }
 
     /**