Fix browser test regarding spellcheck settings

.github/config-test.inc.php

@@ -29,4 +29,5 @@ $config['plugins'] = [
 
 $config['archive_mbox'] = 'Archive';
 
+$config['enable_spellcheck'] = true;
 $config['spellcheck_engine'] = 'pspell';

tests/Browser/README.md

@@ -17,7 +17,7 @@ Installation:
 0. Note that the suite requires PHP >= 7.2 and PHPUnit >= 7.5.
 1. Install Laravel Dusk with all dependencies.
 ```
-composer require "laravel/dusk:~6.9.0"
+composer require "laravel/dusk:~6.17.0"
 ```
 2. Install Chrome WebDriver for the version of Chrome/Chromium in your system. Yes,
    you have to have Chrome/Chromium installed.