Added construction message to readme

Author: numtel

README.md

@@ -7,6 +7,12 @@ Built using the [`zongji` Binlog Tailer](https://github.com/nevill/zongji) and [
 * [Example Application using Express, SockJS and React](https://github.com/numtel/reactive-mysql-example)
 * [Meteor package for reactive MySQL](https://github.com/numtel/meteor-mysql)
 
+## Under construction
+
+This package has only been tested to work in MySQL 5.5.40.
+
+Support for MySQL 5.6 is currently underway.
+
 ## Installation
 
 * Add the package to your project: