execute method remove the call for validate method.
Slack client needs its own SlackClientException similar to PagerDutyClientException.
Update junit tests accordingly.
update severity of notifications, Urgent vs Normal
Reference
Config validation happens when a user creates/modifies a Notification from the UI. It should not be possible for invalid config to exist at this point in processing.
Reference Config validation happens when a user creates/modifies a Notification from the UI. It should not be possible for invalid config to exist at this point in processing.
_Originally posted by @waab76 in https://github.com/Graylog2/graylog-plugin-integrations/pull/595#discussion_r512238987_