Add note about 4.2

Author: barryvdh

readme.md

@@ -1,10 +1,11 @@
-# Laravel Async Queue Driver
+# Laravel 4.2+ Async Queue Driver
 ## Push a function/closure to the background.
 
 Just like the 'sync' driver, this is not a real queue driver. It is always fired immediatly.
 The only difference is that the closure is sent to the background without waiting for the response.
 
 > **Note:** If you are coming from 0.1.0 (or dev-master), you will need to run the migrations, since the new versions uses a database to store the queue.
+> If you are on Laravel 4.0 or 4.1, you can still require 0.1.x for the old way.
 
 ### Install
 Add the package to the require section of your composer.json and run `composer update`