Add test for --thanks

tests/Unit/Plugins/Thanks.php

@@ -0,0 +1,14 @@
+<?php
+
+use Pest\Plugins\Thanks;
+use Symfony\Component\Console\Output\BufferedOutput;
+
+it('outputs funding options when --thanks is used')->skip('The plugin uses `exit()` so not sure how to implement this');
+
+it('does not output funding options when --thanks is not used', function () {
+    $output = new BufferedOutput();
+    $plugin = new Thanks($output);
+
+    $plugin->handleArguments(['foo', 'bar']);
+    assertEquals('', $output->fetch());
+});