auth: Keyroller first import

[chbruyand]

Short description

This is a basic utility to perform automatic keyrolls. This currently only support the pre-publish method but should be extendable.

Checklist

I have:

• [x] read the CONTRIBUTING.md document
• [ ] compiled this code
• [x] tested this code
• [x] included documentation (including possible behaviour changes)
• [ ] documented the code
• [ ] added or modified regression test(s)
• [ ] added or modified unit test(s)