Put asciidoc fix into template with the rest of the markup css

Also remove padding from the asciidoc code block so first line doesn't get indented

lib/gollum/frontend/public/gollum/css/gollum.css

@@ -10,17 +10,6 @@
   A basic stylesheet for Gollum
 */
 
-/*
-  Fixes AsciiDoc listing block rendering.
-  Must be !important to override
-  .markdown-body code, .markdown-body tt {
-  in template.css.
-  https://github.com/github/gollum/issues/278
-*/
-pre > tt {
-  white-space: pre !important;
-}
-
 /* @section core */
 body, html {
   font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;

lib/gollum/frontend/public/gollum/css/template.css

@@ -331,6 +331,7 @@ a.absent {
   background-color: #f8f8f8;
   border-radius: 3px;
 }
+.markdown-body pre>tt,
 .markdown-body pre>code {
   margin: 0;
   padding: 0;