Remove slack outgoing webhook functionality

[timja]

They're deprecated and I don't believe anyone is using this feature:
https://api.slack.com/custom-integrations/outgoing-webhooks

Fixes #281
Fixes #283

See #160 (comment)

If anyone is using this feature and would like it restored, raise an issue about it and we can discuss either restoring it or adding the required feature for the slack app functionality

[mecorusfc]

What does this mean? Does this mean that I can't have a job notify Slack any more? If so, we need this feature.

[timja]

No it doesn’t mean that

It means the feature that allowed you to send messages in slack to trigger jobs etc has been removed.

(It was never documented and didn’t work when authentication was required and had some other quirks)

[JamesXNelson]

so, is there any other way of creating a slack bot? we were recently discussing doing this at one of my clients.

[timja]

not currently implemented in this plugin, but you would probably use slash commands in a slack app

[jetersen]

@JamesXNelson plenty of ways.

depends what you need?

Options include:

Frameworks:
Use Slack's own framework Bolt (javascript): https://slack.dev/bolt/concepts
Use Botkit (javascript): https://botkit.ai allows you to bots for most chat platforms
Use Microsoft Botframework (c#, javascript): https://www.botframework.com

Otherwise there are plenty of libraries:
https://api.slack.com/community

We use a older version of Botkit but it still works just fine :)
Though for our current needs we properly want to switch to Microsoft BotFramework and develop using C#