Support channel override

[spesnova]

Changes

• Rename webhook to webhook_url
• Support channel override

  REF

slack

Channel Override

Incoming webhooks have a default channel, but it can be overridden in your JSON payload. A public channel can be specified with "channel": "#other-channel", and a Direct Message with "channel": "@username".

slack-notifier

Once a notifier has been initialized, you can update the default channel and/or user. https://github.com/stevenosloan/slack-notifier#setting-defaults

[spesnova]

It works