A human plus a googlebot could do it though! Have the bot scan the incoming messages, provide possible facts related instantly. Then the human writes the response. The Turing test would say Robot but it would not be entirely right.
The point of the Turing test is for an AI to pretend to be human so well, humans can't tell if it's human or not. The bots in the Alexa Prize do not have to pretend to be human, and can be very different from humans. The point is just to make bots that are interesting or useful to talk to.