title: Prevent Atom from adding end of file newlines for certain file extensions
body: <p>I have this in my <code>config.cson</code>:</p>
  
  <pre><code>".java.source":
    whitespace:
      removeTrailingWhitespace: false
  ".plain.text":
    whitespace:
      removeTrailingWhitespace: false
  </code></pre>
  
  <p>It works for <code>.java</code> files and <code>.txt</code> files. However, I also want it to work for specific file extensions that I don't have a scope name for.</p>
  
  <p>E.g. when I edit a <code>.foobar</code> file, Atom treats it as plain text. However, it still adds a trailing newline. How do I prevent this?</p>