Added KatoIM support

[kzaitsev]

Added KatoIM support

notify:
  katoim:
    room_id: $$KATOIM_ROOM_ID
    on_started: true
    on_failure: true
    on_success: true

[bradrydzewski]

Awesome! Two very minor comments

1. Instead of using booleans, how do you feel about strings, similar to this:
   https://github.com/drone/drone/blob/master/plugin/notify/email/email.go

The thought is that if we omit on_started it will default to false. This would allow you to omit on_started and assume that means you want to send messages. Just an idea. Let me know if you like it.

2. could we put this in a sub folder notify/kadoim? I'm starting to move all plugins into their own separate folders.

Thanks again!

[kzaitsev]

@bradrydzewski nice idea

i set Started, Success, Failure as strings, now by default enabled only Success and Failure

Also we need to share this code with other notifications plugins
https://github.com/Bugagazavr/drone/blob/katoim/plugin/notify/katoim/katoim.go#L111-L139

Any idea when this can be placed?

[bradrydzewski]

@Bugagazavr awesome. It would be great to share this logic in the notify package but that would create a circular dependency. I'd like to treat all plugins like the remote package where they get registered at runtime, however, this complicates the yaml parsing.

I'll open an issue where we document and discuss some design ideas.