Fixed pagination retrieval.

Per the Github API v3 documentation: "The linebreak is included for
readability". The actual pagination separator is ",".
Ref: http://developer.github.com/v3/#pagination

Author: nfrp

lib/Github/HttpClient/HttpClient.php

@@ -230,7 +230,7 @@ protected function decodePagination(MessageInterface $response)
         }
 
         $pagination = array();
-        foreach (explode("\n", $header) as $link) {
+        foreach (explode(',', $header) as $link) {
             preg_match('/<(.*)>; rel="(.*)"/i', trim($link, ','), $match);
 
             if (3 === count($match)) {

test/Github/Tests/HttpClient/HttpClientTest.php

@@ -6,7 +6,7 @@
 use Buzz\Message\Response;
 
 /**
- * HttpClient test case 
+ * HttpClient test case
  *
  * @author Leszek Prabucki <leszek.prabucki@gmail.com>
  */
@@ -166,7 +166,7 @@ public function shouldHandlePagination()
         $options    = array('c' => 'd');
 
         $response = new Response();
-        $response->addHeader("Link:<page1>; rel=\"page2\"\n<page3>; rel=\"page4\"");
+        $response->addHeader("Link:<page1>; rel=\"page2\", \n<page3>; rel=\"page4\"");
 
         $browser = $this->getBrowserMock();
         $browser