title: .babelrc ignore field seems to be ignored
body: <p>I've got a <code>.babelrc</code> file at the root of a project:</p>
  
  <pre><code>{
    "presets": ["es2015"],
    "ignore": [
      "src"
    ]
  }
  </code></pre>
  
  <p>When I compile it with <code>babel src --out-dir dist</code>, the <code>src</code> folder is still compiled onto the <code>dist</code> folder.</p>
  
  <p>However, when I launch the command <code>babel src --out-dir dist --ignore src</code>, nothing is compiled.</p>
  
  <p>Why is the <code>ignore</code> property of my <code>.babelrc</code> being ignored?</p>
  
  <p>By the way, I've tried with some subfolder or files, and the same issue occurs.</p>