修复seeder错误；删除第三方的think迁移工具，在extend中重新实现；

extend/think/migration/command/stubs/factory.stub

@@ -0,0 +1,11 @@
+<?php
+
+use Faker\Generator as Faker;
+use think\migration\Factory;
+
+/** @var Factory $factory */
+$factory->define("ModelClass", function (Faker $faker) {
+    return [
+        //
+    ];
+});

extend/think/migration/command/stubs/migrate.stub

@@ -0,0 +1,33 @@
+<?php
+
+use think\migration\Migrator;
+use think\migration\db\Column;
+
+class MigratorClass extends Migrator
+{
+    /**
+     * Change Method.
+     *
+     * Write your reversible migrations using this method.
+     *
+     * More information on writing migrations is available here:
+     * http://docs.phinx.org/en/latest/migrations.html#the-abstractmigration-class
+     *
+     * The following commands can be used in this method and Phinx will
+     * automatically reverse them when rolling back:
+     *
+     *    createTable
+     *    renameTable
+     *    addColumn
+     *    renameColumn
+     *    addIndex
+     *    addForeignKey
+     *
+     * Remember to call "create()" or "update()" and NOT "save()" when working
+     * with the Table class.
+     */
+    public function change()
+    {
+
+    }
+}

extend/think/migration/command/stubs/seed.stub

@@ -0,0 +1,19 @@
+<?php
+
+use think\migration\Seeder;
+
+class SeederClass extends Seeder
+{
+    /**
+     * Run Method.
+     *
+     * Write your database seeder using this method.
+     *
+     * More information on writing seeders is available here:
+     * http://docs.phinx.org/en/latest/seeding.html
+     */
+    public function run()
+    {
+
+    }
+}