Greet new users, a la Slack's bot

[joemcl]

One cool feature of Slack is the slackbot, which greets new users and does a quick walk through of an "interactive" set up/tutorial. A similar feature for hubot-mattermost would be useful and cool.
For example:
[1:44 PM]
slackbot I can help you set up your profile. Type your first name, or just type no.
[1:49 PM]
joe Joe
[1:49 PM]
slackbot Okay, Joe. What's your last name?
[1:49 PM]
joe McLaughlin
[1:49 PM]
slackbot You're doing admirably. I'll leave you to it! If you'd like some great tips for team admins and a deeper understanding of how Slack works, check out our handy guide to Making Slack work for your team.