Ping Event for Webhooks

With the release of our new webhook UI, we included a new ping event that webhooks will receive. When you create a new webhook, we will send this event as an initial test of the webhook.

The ping is only informational, doesn't need to be responded to in a specific way, and nothing bad will happen if you respond with an error. It's just a quick "hello world" to let you know you set everything up correctly.

We also added a ping endpoint to the hooks API. By using ping instead of test, you can ensure you won't be limited by the push event requirement that the test endpoint has.