Note: the default endpoint includes the versioned path (https://api.honeybadger.io/v1/). That way, you can have <custom-endpoint>/notices and /checkins instead of being forced to use the same pathv1` in your custom endpoint.

I like this in theory, but in all of our other clients, endpoint is assumed to be an instance of Honeybadger (i.e. an on-prem install), and the version info is included in the pathname after the user has provided the endpoint. Let's do that here to be consistent.

So if I configure "https://api.example.com", then it should send errors to "https://api.example.com/v1/notices"