title: Wicked PDF ignores bootstrap grid system
body: <p>in my template x.pdf.erb site i have linked all the stylesheets and javascript tags:</p>
  
  <pre><code>           &lt;%= wicked_pdf_stylesheet_link_tag "bootstrap.css" -%&gt;
              &lt;%= wicked_pdf_stylesheet_link_tag "style.css" -%&gt;
              &lt;%= wicked_pdf_stylesheet_link_tag "styleUmowa.css" -%&gt;
              &lt;%= wicked_pdf_stylesheet_link_tag "animate.css" -%&gt;
              &lt;%= wicked_pdf_javascript_include_tag "application" %&gt;
  </code></pre>
  
  <p>When the pdf site is generated, everything is good except bootstrap grid system, i mean wicked pdf ignores my:</p>
  
  <pre><code>&lt;div class="container"&gt;
     &lt;div class="row"&gt;
         &lt;div class="col-lg-4"&gt;&lt;/div&gt;
         &lt;div class="col-lg-4"&gt;&lt;/div&gt;
         &lt;div class="col-lg-4"&gt;&lt;/div&gt;
     &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>So, it`s displayed like normal divs without bootstrap grid. Can you help me with this?</p>