Please update your documentation to mention that http(s)-outbound does NOT work with libraries like `request` which doesn't use callback when making http.request

[exp-dev-dj]

trafficstars

'http-outbound'/'https-outbound' events return undefined response statusCode if client uses request, request-promise or any other http libraries that do not use callback when making http.request. You mention this in the code comment (https://github.com/RuntimeTools/appmetrics/blob/master/probes/http-outbound-probe.js#L91), but there is no explanation on work-around for popular http libraries such as 'request', 'request-promise', 'node-fetch'... (node, 'axios' works)