Configuring composer.json to use the 2.5 version

Configuring composer.json to use the 2.5 version Rather than 2.4

Author: danielsan

book/from_flat_php_to_symfony2.rst

@@ -480,8 +480,8 @@ the HTTP response being returned. Use them to improve the blog:
     // echo the headers and send the response
     $response->send();
 
-.. versionadded:: 2.5
-    Support for HTTP status code constants was introduced in Symfony 2.5.
+.. versionadded:: 2.4
+    Support for HTTP status code constants was introduced in Symfony 2.4.
 
 The controllers are now responsible for returning a ``Response`` object.
 To make this easier, you can add a new ``render_template()`` function, which,