title: Set Content-Type created file with Ruby File?
body: <p>I'm using <code>File.open</code> to create a <code>.csv</code> file on the fly.</p>
  
  <p>But what I need to do is set the <code>Content-Type</code> of the file to <code>binary/octet-stream</code> so that the browser will automatically download it instead of just displaying the contents of it in the browser.</p>
  
  <p>The file itself is created locally and then uploaded to Amazon S3.</p>