As you might have heard,
Laravel 5.6 is out with lots of new stuff packed for developers.
Here's what you need to know before migrating your website from
Laravel 5.6 requires you to have
PHP 7.1.13 or higher
So if you're looking to migrate your project to
Laravel 5.6, you need to make sure your machine is running on
7.1.13 or higher.
Change phpunit/phpunit version to ~7.0
Well thats the most basic steps to do, try & run
composer update & see if everything works as it was before.
You may follow this guide for more detailed information.
Also Read: How to Learn Laravel