Add Guard for easier testing
Add :whitelist and :blacklist support
Remove Ruby 1.9.2 ... add 2.1.1

1.9.2 is finicky with guard and pretty deprecated.
Improve spec, add whitelist special case
Refactor exclusions out of make_html, add comment to spec
Simplify code
Merge pull request #70 from SamSaffron/master

Add whitelist and blacklist support