Allow for creating an Auditable model even if application is not spun up (#962)

* unlint

* ends with new line

* Check facade instance

---------

Co-authored-by: erikn69 <[email protected]>

Author: cosmastech

src/Auditable.php

@@ -75,7 +75,7 @@ trait Auditable
      */
     public static function bootAuditable()
     {
-        if (static::isAuditingEnabled()) {
+        if (App::getFacadeRoot() && static::isAuditingEnabled()) {
             static::observe(new AuditableObserver);
         }
     }

tests/Unit/OutsideOfAppContextTest.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace OwenIt\Auditing\Tests\Unit;
+
+use OwenIt\Auditing\Tests\Models\Article;
+use PHPUnit\Framework\TestCase;
+
+class OutsideOfAppContextTest extends TestCase
+{
+    public function test_can_create_new_model(): void
+    {
+        $article = new Article();
+        $this->assertInstanceOf(Article::class, $article);
+    }
+}