Work on incorporating Guard.
Correct missing Mime error.
Continue Guard work.
Fix issue with loading Jekyll config.
Fix bug with directory requests.
Skip using Thor's invoke; Read config from files.

Since the isolation middleware needs to modify the isolation config
Guard needs to read that config from a file (or else I need to figure
out how to pass a hash back and forth).
Add Rubocop and correct style.
Style fixes.
Add options to serve future and draft posts.
Set case statement style to Ruby standard.