Updated readme

Readme.md

@@ -83,7 +83,7 @@ public function SendMsgViaMqtt($topic, $message)
         return false;
 }
 ```
-### Tested on php 7.3 and laravel 5.7 
+### Tested on php 7.3 and laravel 5.7 and also laravel 5.8
 
 ### Subscribing part under development