title: Bold text does not work with Axlsx ruby gem
body: <p>This style only aligns left, the font is not bold.</p>
  
  <pre><code>    bold_italic = styles.add_style :b =&gt; true, :i =&gt; true 
      bold        = styles.add_style :b =&gt; true
      yellow_bg   = styles.add_style :b =&gt; true, :bg_color =&gt; 'FFF60B',
  
      sheet.add_row ['År:', Time.now.year, "Pågår"],  
        :style =&gt; [bold_italic, yellow_bg, bold]
  </code></pre>
  
  <p>The yellow_bg styling also works. Is there a new syntax for getting the font bold?</p>