Use Slack notification name field instead of channel.

[iris-garcia]

Sysdig REST API returns Slack channel name as response['name'] instead of response['options']['channel'] (which is empty):

Example of curl GET (/api/notificationChannels)

{"notificationChannels":[{"id":865,"version":1,"createdOn":1602011148000,"modifiedOn":1602011148000,"teamId":1111,"type":"SLACK","enabled":true,"sendTestNotification":false,"name":"#channel","options":{"notifyOnOk":true,"url":"https://this-is-a-test.ok/123","channel":"","notifyOnResolve":true}}

Integrating this pull request, it would be possible to filter Slack notification channels by using the name field, currently it is not possible to filter by channel name.

[tembleking]

Hi @iris-garcia, thanks for your contribution. As I mentioned in #149, secrets are not mounted into PRs from forked repositories. That's a known limitation in GitHub Actions.
We will review and test this PR.

[tembleking]

Hey Iris, I am merging this, thanks for your contribution! 💯