migrate to pest php for testing

tests/Pest.php

@@ -0,0 +1,28 @@
+<?php declare(strict_types=1);
+
+/*
+|--------------------------------------------------------------------------
+| Test Case
+|--------------------------------------------------------------------------
+|
+| The closure you provide to your test functions is always bound to a specific PHPUnit test
+| case class. By default, that class is "PHPUnit\Framework\TestCase". Of course, you may
+| need to change it using the "pest()" function to bind a different classes or traits.
+|
+*/
+
+/*
+|--------------------------------------------------------------------------
+| Functions
+|--------------------------------------------------------------------------
+|
+| While Pest is very powerful out-of-the-box, you may have some testing code specific to your
+| project that you don't want to repeat in every file. Here you can also expose helpers as
+| global functions to help you to reduce the number of lines of code in your test files.
+|
+*/
+
+function something(): void
+{
+    // ..
+}