Handle slackbot responses for the slack bridge

[polypixeldev]

Whenever there is a slackbot response in the bridge channel, a warning is raised like this:

[com.slack.api.bolt.App]: No BoltEventHandler registered for event: message:slackbot_response
---
[Suggestion] You can handle this type of event with the following listener function:
app.event(MessageSlackbotResponseEvent.class, (payload, ctx) -> {
return ctx.ack();
});

[polypixeldev]

Slackbot responses aren't documented and seem to not be in the java slack SDK.