title: How to install Guzzle 6 in Laravel?
body: <p>I need install <code>Guzzle 6</code> in Laravel 5.6.</p>
  
  <p>I run this code:</p>
  
  <p>composer require php-http/guzzle6-adapter</p>
  
  <p>But after run this code, show error:</p>
  
  <pre><code>./composer.json has been updated
  Loading composer repositories with package information
  Updating dependencies (including require-dev)
  Package operations: 3 installs, 0 updates, 0 removals
    - Installing guzzlehttp/promises (v1.3.1): Downloading (100%)         
    - Installing guzzlehttp/guzzle (6.3.2): Downloading (100%)         
    - Installing php-http/guzzle6-adapter (v1.1.1): Downloading (100%)         
  
  Writing lock file
  Generating optimized autoload files
  &gt; Illuminate\Foundation\ComposerScripts::postAutoloadDump
  &gt; @php artisan package:discover
  PHP Fatal error:  Uncaught ReflectionException: Class 
  App\Console\Kernel does not exist in   
  /vendor/laravel/framework/src/Illuminate/Container/Container.php:767
  Stack trace:
  #0 
  /vendor/laravel/framework/src/Illuminate/Container/Container.php(767): 
  ReflectionClass-&gt;__construct('App\\Console\\Ker...')
  #1  
  /vendor/laravel/framework/src/Illuminate/Container/Container.php(646): 
  Illuminate\Container\Container-&gt;build('App\\Console\\Ker...')
  #2         
  vendor/laravel/framework/src/Illuminate/Container/Container.php(601):             
  Illuminate\Container\Container-&gt;resolve('App\\Console\\Ker...', Array)
  #3 /ven 
  dor/laravel/framework/src/Illuminate/Foundation/Application.php(740): 
  Illuminate\Container\Container-&gt;make('App\\Console\\Ker...', Array)
  #4 
  /vendor/laravel/framework/src/Illuminate/Container/Container.php(256):     
  Illuminate\Foundation\Appl in 
  /vendor/laravel/framework/src/Illuminate/Container/Container.php on 
  line 767
  Script @php artisan package:discover handling the post-autoload-dump 
  event returned with error code 255
  </code></pre>
  
  <p>I wanted install mailgun pakage in laravel 5.6.</p>
  
  <p>Update 1:</p>
  
  <p>My Composer.json file is this code:</p>
  
  <pre><code>{
  "name": "laravel/laravel",
  "description": "The Laravel Framework.",
  "keywords": ["framework", "laravel"],
  "license": "MIT",
  "type": "project",
  "require": {
      "php": "&gt;=7.1.3",
      "bogardo/mailgun": "^5.0",
      "cviebrock/eloquent-sluggable": "^4.5",
      "fideloper/proxy": "~4.0",
      "intervention/image": "^2.4",
      "laravel/framework": "5.6.*",
      "laravel/tinker": "~1.0",
      "laravelcollective/html": "^5.6",
      "php-http/guzzle6-adapter": "^1.1",
      "pusher/pusher-php-server": "^3.0",
      "uxweb/sweet-alert": "^1.4"
  },
  "require-dev": {
      "filp/whoops": "~2.0",
      "nunomaduro/collision": "~1.1",
      "fzaninotto/faker": "~1.4",
      "mockery/mockery": "~1.0",
      "phpunit/phpunit": "~7.0",
      "symfony/thanks": "^1.0"
  },
  "aXutoload": {
      "classmap": [
          "database/seeds",
          "database/factories"
      ],
      "psr-4": {
          "App\\": "app/"
      }
  },
  "autoload-dev": {
      "psr-4": {
          "Tests\\": "tests/"
      }
  },
  "extra": {
      "laravel": {
          "dont-discover": [
          ]
      }
  },
  "scripts": {
      "post-root-package-install": [
          "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
      ],
      "post-create-project-cmd": [
          "@php artisan key:generate"
      ],
      "post-autoload-dump": [
          "Illuminate\\Foundation\\ComposerScripts::postAutoloadDump",
          "@php artisan package:discover"
      ]
  },
  "config": {
      "preferred-install": "dist",
      "sort-packages": true,
      "optimize-autoloader": true
  },
  "minimum-stability": "dev",
  "prefer-stable": true
  }
  </code></pre>
  
  <p>I need install Guzzle 6 in Laravel 5.6.</p>
  
  <p>I use this package: <a href="https://packalyst.com/packages/package/bogardo/mailgun" rel="nofollow noreferrer">https://packalyst.com/packages/package/bogardo/mailgun</a></p>
  
  <p>How to issue this problem?</p>