title: YamlLint validation
body: <p>I have a Yaml file like this </p>
  
  <pre><code>    name: hhh_aaa_bbb 
  arguments:
      - !argument
          name: inputsss
          description: hhh aaa bbb
          required: true
      - !argument
          name: lll
          description: lll
          required: true
      - !argument
          name: ccc
          description: ccc
          required: true
  source:
      !!com.abc.bbc.sss
          uri: !arg input
  </code></pre>
  
  <p>But when I use Yaml Lint to validate this yaml file in <a href="http://www.yamllint.com/" rel="nofollow">yamllint</a>,it removes all the "!" or "!!"  user arguments. Why does that happen?</p>
  
  <p>This is the output i get from yaml lint after validation</p>
  
  <pre><code>    --- 
  arguments: 
    - 
      description: "hhh aaa bbb"
      name: inputsss
      required: true
    - 
      description: lll
      name: lll
      required: true
    - 
      description: ccc
      name: ccc
      required: true
  name: hhh_aaa_bbb
  source: 
    uri: input
  </code></pre>