public function up()
    {
        $platform = \DB::getDoctrineSchemaManager()->getDatabasePlatform();
        $platform->registerDoctrineTypeMapping('enum', 'string');

        Schema::table('posts', function (Blueprint $table) {
            $table->text('excerpt')->nullable()->change();
            $table->text('meta_description')->nullable()->change();
            $table->text('meta_keywords')->nullable()->change();
        });
    }