title: SonataAdmin Install issue
body: <p>I trying to install SonataAdmin on my Symfony Project but at the end of the part-2 of the documention when i'm trying to go on "<a href="http://localhost:8000/admin/" rel="nofollow noreferrer">http://localhost:8000/admin/</a>" I have a error : <em>"You have requested a non-existent service "admin.category" in . (which is being imported from "C:\wamp64\www\Sonata/app/config\routing.yml"). Make sure there is a loader supporting the "sonata_admin" type."</em></p>
  
  <p>I have no idea why, i give give my all my parameters code maybe it's can help you to understand my problem. </p>
  
  <p>parameters:
      #parameter_name: value</p>
  
  <p>services:</p>
  
  <pre><code># default configuration for services in *this* file
  _defaults:
      # automatically injects dependencies in your services
      autowire: true
      # automatically registers your services as commands, event subscribers, etc.
      autoconfigure: true
      # this means you cannot fetch services directly from the container via $container-&gt;get()
      # if you need to do this, you can override this setting on individual services
      public: false
  
  admin.category:
      class: AppBundle\Admin\CategoryAdmin
      arguments: [~, AppBundle\Entity\Category, ~]
      tags:
          - { name: sonata.admin, manager_type: orm, label: Category }
  
  
  # makes classes in src/AppBundle available to be used as services
  # this creates a service per class whose id is the fully-qualified class name
  AppBundle\:
      resource: '../../src/AppBundle/*'
      # you can exclude directories or files
      # but if a service is unused, it's removed anyway
      exclude: '../../src/AppBundle/{Entity,Repository,Tests}'
  
  # controllers are imported separately to make sure they're public
  # and have a tag that allows actions to type-hint services
  AppBundle\Controller\:
      resource: '../../src/AppBundle/Controller'
      public: true
      tags: ['controller.service_arguments']
  
  # add more services, or override services that need manual wiring
  # AppBundle\Service\ExampleService:
  #     arguments:
  #         $someArgument: 'some_value'
  </code></pre>
  
  <p>`</p>
  
  <p>The indentation is going wrong i add you a picture of this file. <a href="https://i.stack.imgur.com/ncO7Q.png" rel="nofollow noreferrer">Service code</a></p>