Add sequel gem dependency
Use proper gem naming patterns

The RubyGems community has a very common convention for naming gems,
where the underscore (_) indicates a word separation, and classes will
be named with camel-case using. So karat_sleuth => KaratSleuth.

Originally we had been using the gem name KaratSleuth which is
incorrect.

See here: http://guides.rubygems.org/patterns/
Add Storage module for handling db persisting

This module handles setting up the Sequel database connection as well as
adding methods to the Bayes classifier for persisting the classification
categories.
Ignore the database file in git

Don't want to accidentally commit this
Very rudimentary classification persistence

This appears to be very slow right now. This could also probably be done
in a much cleaner fashion, but this should be good for a proof of
concept for now