Laravel，Changing columns for table “permissions” requires Doctrine DBAL

执行php artisan migration时提示：

[RuntimeException]
  Changing columns for table "permissions" requires Doctrine DBAL; install "doctrine/dbal".

解决方法：

配置：composer.json

    "require": {
        ...
        "doctrine/dbal": "v2.4.2"
    },

然后执行：

composer update