Don't create Error when we want to return a message.
Don't create Error when we want to return a message.

jinpark/pongbot-2,jinpark/pongbot-2,andrewvy/slack-pongbot,andrewvy/slack-pongbot,garukun/slack-pongbot,geoffrey/slack-pongbot,geoffrey/slack-pongbot,clementmiao/slack-smashbot,garukun/slack-pongbot