Print help messages

[wallacyyy]

The bot needs to print the commands when someone types @botname coffeepoll help.
Should be this message:

Commands:
  hubot coffeepoll near <text> - Configure the place for next polls
  hubot coffeepoll start - Start the poll
  hubot coffeepoll vote <number> - Vote in one of poll options
  hubot coffeepoll partial - Show the partial results
  hubot coffeepoll finish - Finish the poll

One test is needed :)