Add LDAP test cases to group

TESTING.md

@@ -45,8 +45,21 @@ DB_PASSWORD={}
 
 Now you are ready to run the entire test suite from your terminal:
 
-`php artisan test`
+```shell
+php artisan test
+````
 
 To run individual test files, you can pass the path to the test that you want to run:
 
-`php artisan test tests/Unit/AccessoryTest.php`
+```shell
+php artisan test tests/Unit/AccessoryTest.php
+```
+
+Some tests, like ones concerning LDAP, are marked with the `@group` annotation. Those groups can be run, or excluded, using the `--group` or `--exclude-group` flags:
+
+```shell
+php artisan test --group=ldap
+
+php artisan test --exclude-group=ldap
+```
+This can be helpful if a set of tests are failing because you don't have an extension, like LDAP, installed.

tests/Unit/LdapTest.php

@@ -7,6 +7,9 @@ use Exception;
 use Tests\Support\InteractsWithSettings;
 use Tests\TestCase;
 
+/**
+ * @group ldap
+ */
 class LdapTest extends TestCase
 {
     use InteractsWithSettings;