Case-insensitive on just markdown

Author: bkeepers

lib/github/markup/implementation.rb

@@ -21,7 +21,7 @@ def match?(filename)
 
     private
       def file_ext_regexp
-        @file_ext_regexp ||= /\.(#{regexp})\z/i
+        @file_ext_regexp ||= /\.(#{regexp})\z/
       end
     end
   end

lib/github/markup/markdown.rb

@@ -25,7 +25,7 @@ class Markdown < Implementation
       }
 
       def initialize
-        super(/md|rmd|mkdn?|mdwn|mdown|markdown|litcoffee/)
+        super(/md|rmd|mkdn?|mdwn|mdown|markdown|litcoffee/i)
       end
 
       def load