title: composer update laravel 5.5 to laravel 5.6 gets hangs with updating dependencies (including require-dev)
body: <p>I am upgrading my laravel project to 5.6. current version is 5.5.44. my composer file is as below. when i run composer update, it does nothing but showing Loading composer repositories with package information Updating dependencies (including require-dev) in the terminal for hours. what would be the issue for this?</p>
  
  <pre><code>"require": {
          "php": "&gt;=7.1.3",
          "fideloper/proxy": "~4.0",
          "laravel/framework": "5.6.*",
          "laravelcollective/html": "^5.7",
          "nesbot/carbon": "^1.33",
          "maximebf/debugbar": "~1.15.0",
          "barryvdh/laravel-debugbar": "^3.2",
          "yajra/laravel-datatables-oracle": "~6.0",
          "artem-schander/l5-modular": "dev-master",
          "intervention/image": "^2.3",
          "hesto/multi-auth": "^1.0",
          "laravel/cashier": "~7.0",
          "laravel-notification-channels/twilio": "^2.0",
          "guzzlehttp/guzzle": "^6.2",
          "laravel/socialite": "2.0.*",
          "barryvdh/laravel-snappy": "^0.4.3",
          "psr/simple-cache": "^1.0",
          "psr/container": "^1.0",
          "phpoffice/phpexcel": "^1.8",
          "phpoffice/phpspreadsheet": "^1.6",
          "doctrine/inflector": "^1.3",
          "symfony/translation": "^4.2"
      },
      "require-dev": {
          "fzaninotto/faker": "~1.4",
          "mockery/mockery": "0.9.*",
          "phpunit/phpunit": "^7.1.5",
          "symfony/css-selector": "3.1.*",
          "symfony/dom-crawler": "3.1.*",
          "filp/whoops": "~2.0"
      },
  
  
  
  $ php artisan --version
  Laravel Framework 5.5.44
  $ composer update
  Loading composer repositories with package information
  Updating dependencies (including require-dev)
  </code></pre>