Let's get started!
First, setup a slash command in Slack. You can do that here: https://slack.com/apps/A0F82E8CA-slash-commands
You'll install the slash comamnds "app" to your slack account. Once you've got that setup, continue below.
Ok now that it's installed, setup a slash command.
We're going to use /tonic as our prefix here. Use the following values:
command: /tonic
url: https://tonicdev.io/matt/56aa6f873c22eb0d00bb37c0/branches/master/tonic
method: POST