update readme

Author: aivis

README.md

@@ -18,7 +18,7 @@ This packages provides a full abstraction for Understand.io and provides extra f
 1. Add the package to your project
 
 ```
-composer require understand/understand-laravel5:^2
+composer require understand/understand-laravel5
 ```
 
 2. Add the ServiceProvider to the `providers` array in `config/app.php`