How to create PDF from Rpresentation or Slidify-presentation
      ========================================================
      author: jebsel
      date: 30/03/2015
      transition: rotate

      First Slide
      ========================================================
      <p align="right"><img style="width:90px;height:70px;border:0;"src="logo_alpha.png"></img></p>

      I have absolutely no clue how to extract direct to pdf, can you help?
      Thanks in advance!