Minor refactoring of Bayes#untrain.
Minor refactoring of Bayes#untrain.

https://github.com/cardmagic/classifier/pull/6

jekyll/classifier-reborn,MadBomber/classifier-reborn,kreynolds/classifier-reborn,MadBomber/classifier-reborn,jekyll/classifier-reborn,sanbiv/classifier-reborn,kreynolds/classifier-reborn,sanbiv/classifier-reborn