[1.7.0] Add the option to set values & db name during tenant creation (#86)

* Add the option to set values & db name during tenant creation

* Apply fixes from StyleCI

* Add tests

* Apply fixes from StyleCI

* Rewrite conditional for clarity

src/Exceptions/CannotChangeUuidOrDomainException.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Stancl\Tenancy\Exceptions;
+
+class CannotChangeUuidOrDomainException extends \Exception
+{
+    protected $message = 'Uuid and domain cannot be changed.';
+}