Really like the announcement of botkit[1], I was just looking at adding a vote bot to our slack and only found a really old example that ended up not working.
I hope that the official blessings of botkit doesn't negatively impact other bot frameworks that user the Slack APIs. Lita (https://www.lita.io/) is an excellent way to write Slack bots in Ruby. It supports other chat services and protocols too, so your bots don't lock you in to Slack.