Notifier when image update failed

[yuyuvn]

Is your feature request related to a problem? Please describe. When image updater fail (wrong annotation config or other reason), our developer have no idea it is failed and wait forever... We want developer being notified when it is failed to update image, with some information so they can understand why it failed.

Describe the solution you'd like Support slack notifier.

Describe alternatives you've considered Or we can support a web-hook.