migration 文件提示:Method 'create' not found in Illuminate\Support\Facades\Schema 怎么解决？

public function up()
    {
        Schema::create('password_resets', function (Blueprint $table) {
            $table->string('email')->index();
            $table->string('token')->index();
            $table->timestamp('created_at')->nullable();
        });
    }

php7.1
laravel5.4
migration文件
提示:Method 'create' not found in Illuminate\Support\Facades\Schema
求解！