Include timezone offset in new post template for YAML Front-Matter

Closes #1419.

Rakefile

@@ -108,7 +108,7 @@ task :new_post, :title do |t, args|
     post.puts "---"
     post.puts "layout: post"
     post.puts "title: \"#{title.gsub(/&/,'&')}\""
-    post.puts "date: #{Time.now.strftime('%Y-%m-%d %H:%M')}"
+    post.puts "date: #{Time.now.strftime('%Y-%m-%d %H:%M:%S %z')}"
     post.puts "comments: true"
     post.puts "categories: "
     post.puts "---"