Unmarshalling error logs contain Slack user data

[richgerrard]

Describe the bug
When the dependency (nlopes/slack) can't marshall a message event, an error is logged.
The log contains information about the event, which contains much too much information on the Slack user.

To Reproduce
Steps to reproduce the behavior:

1. Go to Slack
2. Click on the huddle icon; do it in a really public channel just to annoy lots of other people with your test. Some of them might join to say hi! Please tell them I said: "hello".
3. Dump the error logs of your botKube pod (k logs botkube-blah)
4. See error

Slack unmarshalling error: RTM Error: Received unmapped event "user_huddle_changed": {all my info about me}

Expected behavior
Don't log things that don't matter.

Screenshots
n/a

Additional context
nlopes/slack has moved to slack-go/slack, and you should probably also update your dependency, but the problem with using this tool is that it listens to every possible slack event.
(ref: https://github.com/slack-go/slack/blob/0e14c9d4a15c91e845bc371fe91ee58763a3813a/websocket_managed_conn.go#L494)
Which means BotKube listens to every event
Which makes this tool a really frightening kind of slack spy program that's running in my kubernetes cluster and outputting employee information in error logs.

[PrasadG193]

Thanks for reporting this. We will prioritize this for the upcoming release

[pkosiec]

Hi @richgerrard,

Thanks for describing the issue. I've checked that, and you're absolutely right—it is caused by the slack-go/slack library. I've prepared a PR with fix directly to the repo: slack-go/slack#1067

Also, to avoid being blocked, I've created a PR with a workaround on BotKube side: #583. I hope it will be merged soon 🤞

Cheers!