Update readme.md

ARACOOOL · ARACOOOL · commit 73aee4c2c11a · 2015-11-15T14:45:59.000+05:00
diff --git a/readme.md b/readme.md
@@ -20,6 +20,9 @@ The recommended way to install library is [through composer](http://getcomposer.
 
 * Cloning the git repository
 
+## Requirements
+dHttp (php curl library) works with PHP 5.4, 5.5, 5.6, and HHVM
+
 ## Usage
 
 ### GET request:
