Ensure that migrations run

php-packages/testing/tests/migrations/2021_05_11_000000_create_table_so_we_can_check_existence.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Flarum\Testing;
+
+use Flarum\Database\Migration;
+use Illuminate\Database\Schema\Blueprint;
+
+return Migration::createTable('testing_table', function (Blueprint $table) {
+    $table->string('id', 100)->primary();
+});