title: Downloading workbook without saving it to disk rubyxl in Rails
body: <pre><code>Rails 4.2
  RubyXL
  </code></pre>
  
  <p>I am using the RubyXL to create a workbook. I can write it disk with:</p>
  
  <pre><code>workbook.write("path/to/desired/Excel/file.xlsx")
  </code></pre>
  
  <p>and then download it with something like this:</p>
  
  <p>send_file(workbook.write("path/to/desired/Excel/file.xlsx"), options = {:filename => 'myworkbook.xlsx', :disposition => 'attachment'})</p>
  
  <p>Any suggestions on how to download it without having to save it to the server first?</p>