Test an app that uses HTTPS

[aguibert]

User story:

As a user of this test framework, I want to test an app that uses HTTPS

Additional detail:

The easiest way to test an HTTP service is using unsecured applications, but in production applications should be communicating via HTTPS, which requires client/server certificates. The test framework should make it easy to drive HTTPS requests to the server.

[aguibert]

It may be good to use a Pebble container for generating certificats using the ACME protocol for testing:
https://github.com/letsencrypt/pebble

[appiepollo14]

Same issue as #306 therefore this one will be closed.