title: merb - wkhtmltopdf command failed
body: <p>when am running command like this its generating pdf document:</p>
  
  <pre><code>$ wkhtmltopdf http://google.com google.pdf
  Loading pages (1/5)
  Resolving links (2/5)                                              
  Counting pages (3/5)                                                      
  Printing pages (5/5)                                                      
  Done   
  </code></pre>
  
  <p>But when using inside app by pdfkit gem it showing error</p>
  
  <pre><code>merb : worker (port 4000) ~ command failed: "/usr/local/bin/wkhtmltopdf" "--page-size" "Letter" "--print-media-type" "--margin-right" "0.0in" "--encoding" "UTF-8" "--margin-top" "0.5in" "--margin-bottom" "0.5in" "--margin-left" "0.0in" "--quiet" "-" "-" - (RuntimeError)
  </code></pre>
  
  <p><strong>what am tried:</strong></p>
  
  <p>setting path </p>
  
  <p><code>config.wkhtmltopdf = '/usr/local/bin/wkhtmltopdf '</code></p>
  
  <p>installing dependencies</p>
  
  <pre><code>sudo aptitude install openssl build-essential xorg libssl-dev
  </code></pre>
  
  <p><strong>Environment</strong></p>
  
  <ul>
  <li>Ubuntu 12.04 amd64 </li>
  <li>merb application  </li>
  <li>ruby 1.8.7</li>
  </ul>