title: PDFKit header or footer not working
body: <p>I am trying to add page numbers to each page of pdf generated using PdfKit. The following is my code :   </p>
  
  <pre><code>content = File.read( "report.html.erb")
  template = ERB.new(content)
  set_margin = 0.to_s
  kit = PDFKit.new(template.result(binding), :header_center =&gt; "Page [page] of [toPage]", page_width: '157.42', page_height: '52.77', :margin_top =&gt; set_margin+'in', :margin_right =&gt; set_margin+'in', :margin_bottom =&gt; set_margin+'in', :margin_left =&gt; set_margin+'in')
  kit.to_file(file_path)
  </code></pre>
  
  <p>No header is getting displayed on the generated pdf. Please provide a solution for this.</p>