acme-dns-tiny: fixup registration process, we can log with account_url only after processing headers

Resolve "Create a script to implement account key rollover"

Closes #3

See merge request !8

To correctly fix it, we need to create a JWS function

use of key thumbprints

* Use more specific test module (we'll create new test modules for future tools)
* Create gitlab-ci job for Debian Jessie and Debian Jessie + backports