Laravel update 5.7&5.8

### laravel 5.7
upgradeページを確認
https://readouble.com/laravel/5.7/ja/upgrade.html

composer.json

"require": {
        "php": ">=7.1.3",
        "laravel/framework": "5.7.*",
        "laravelcollective/html": "5.7.*",
        "cviebrock/eloquent-sluggable": "^4.3",
        "unisharp/laravel-filemanager": "^1.9",
        "intervention/image": "^2.5"
    },

$ php composer.phar update
$ php artisan –version
->エラー
-> Unresolvable dependency resolving [Parameter #0 [ $app ]] in class Illuminate\Support\Manager

config/app.php

Illuminate\Notifications\NotificationServiceProvider::class,

$ php artisan –version

### laravel 5.8
https://readouble.com/laravel/5.8/ja/upgrade.html

composer.json

"require": {
        "php": ">=7.1.3",
        "laravel/framework": "5.8.*",
        "laravelcollective/html": "5.8.*",
        "cviebrock/eloquent-sluggable": "^4.3",
        "unisharp/laravel-filemanager": "^1.9",
        "intervention/image": "^2.5"
    },

$ php artisan –version

criticalな変更はそこまでありませんが、公式のupgrade guideを読むと、セキュリティパッチが多く、やはり最新版に保った方が良さそうだ。