bug fix: support fenced code blocks
bug fix: support fenced code blocks

Fenced code blocks stopped working because of the switch to kramdown, so
configure for the redcarpet markdown renderer.

ref:
http://www.dpetzel.info/tips/jekyll/2015/01/04/jekyll-with-fenced-code-blocks.html

dbrinegar/dbrinegar.github.io,dbrinegar/dbrinegar.github.io