[2.1.0] Fix queue race conditions (#178)

* Add TenantDoesNotExist exception, fix queued migrator serialization

* wip

* Apply fixes from StyleCI

* Use only one config for  queueing

* Apply fixes from StyleCI

* rename test

* rename test

src/Exceptions/TenantDoesNotExistException.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\Exceptions;
+
+use Exception;
+
+class TenantDoesNotExistException extends Exception
+{
+    public function __construct(string $id)
+    {
+        $this->message = "Tenant with this id does not exist: $id";
+    }
+}