add user migration

backend/database/Migration.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace App\Database;
+
+use Illuminate\Database\Capsule\Manager as Capsule;
+use Illuminate\Database\Schema\Builder;
+
+abstract class Migration
+{
+    abstract public function up(): void;
+
+    abstract public function down(): void;
+
+    protected function schema(): Builder
+    {
+        return Capsule::schema();
+    }
+}