Broid-Slack is not working anymore ?

[fungiboletus]

Overview

• What project is this issue for?:
  broid-slack

• Is this a bug, security, feature request, or feedback:

Bug

Details

Slack is not working. The webhook payload format may have changed.

Steps to Reproduce

1. Start Broid with Slack enabled
2. Create a new Slack application
3. Go to Event subscriptions
4. Register a request URL
   5. Unfocus the input, so Slack will test the URL

Observed

Broid-slack has an exception because payloadStr is undefined. It seems like the payload format has changed.

Expected

No exception, request URL validated.

[killix]

Thanks for the report.
The issue is because we didn't handle the verification challenge flow as the integration the real-time API.

I quickly added the support of the flow. But reminder we support only this subscriptions: event_callback, interactive_message, slash_command

related #143