The Slack publisher allows Continua CI to send notifications to Slack users or channels
API Token
This can be a user or bot OAuth access token. Create a Slack App, add the "send messages as app name (chat:write:bot)" Permission Scope and then install it to your team workspace. An OAuth access token is automatically generated and copies be copied to this field.
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The default channel for this publisher to send the message to. Enter a channel name, e.g #general, or a member id to direct all messages to a Slack user. This can be overridden when creating a subscription.
Icon URL
Enter the URL to an image to display as the message app icon. This defaults to the Continua CI icon 
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