We have some internal logos we can pick from. The best bet may be to add a new file to the S3 bucket, unless someone can confirm the following link is only used by the Slack handler. However, it should work with anything else that uses it, as long as a white background is used with it.
Currently, the Slack handler uses the following logo when it posts to a channel if not overridden:
http://s3-us-west-2.amazonaws.com/sensuapp.org/sensu.png
https://github.com/sensu/sensu-slack-handler/blob/master/main.go#L94
We have some internal logos we can pick from. The best bet may be to add a new file to the S3 bucket, unless someone can confirm the following link is only used by the Slack handler. However, it should work with anything else that uses it, as long as a white background is used with it.