General cleanup

Added a config hash to remove all the envvars from logic. Compacted some code for clarity.

The non-whitespace diff https://github.com/hubot-scripts/hubot-auth/compare/v1.0.0...general-cleanup?w=1

Taking the set-as-anything approach for envvars from hubot-irc
https://github.com/nandub/hubot-irc#irc-server-fake-ssl

cc: @Mawalu