Composer namespace + Readme

Author: rmruano

README.md

@@ -10,7 +10,7 @@ Update your `composer` require block:
 
 # Usage
 ```php
-use pubsubhubbub\subscriber\Subscriber;
+use \Pubsubhubbub\Subscriber\Subscriber;
 
 $hub_url      = "http://pubsubhubbub.appspot.com";
 $callback_url = "put your own endpoint here";

composer.json

@@ -15,6 +15,6 @@
         "php": "~5.4 || ~7.0"
     },
     "autoload": {
-        "psr-4": { "pubsubhubbub\\subscriber\\": "src/" }
+        "psr-4": { "Pubsubhubbub\\Subscriber\\": "src/" }
     }
 }

example.php

@@ -7,13 +7,15 @@
 
 include("./src/Subscriber.php");
 
+use \Pubsubhubbub\Subscriber\Subscriber;
+
 $hub_url = "http://pubsubhubbub.appspot.com";
 $callback_url = "put your own endpoint here";
 
 $feed = "http://feeds.feedburner.com/onlineaspect";
 
 // create a new subscriber
-$s = new Pubsubhubbub\Subscriber\Subscriber($hub_url, $callback_url);
+$s = new Subscriber($hub_url, $callback_url);
 
 // subscribe to a feed
 $s->subscribe($feed);