Update GemFile & .gitignore

Updates the Gemfile to fix an issue in windows. Additionally the gitignore
was cleaned up.

.gitignore

@@ -1,10 +1,12 @@
-# Jekyll and Scss
+#############
+## Jekyll
+#############
+.jekyll-metadata
 _site/
-/sass_cache/
 Gemfile.lock
 
 #############
-## Windows 
+## Windows
 #############
 
 # Windows image file caches

Gemfile

@@ -2,3 +2,5 @@ source 'https://rubygems.org'
 require 'rbconfig'
 gem 'wdm', '>=0.1.0' if RbConfig::CONFIG['target_os'] =~ /mswin|mingw/i
 gem 'github-pages'
+# force minimum version of pygments.rb to fix windows issue
+gem 'pygments.rb', '>=0.6.1'