Puppet module to deploy systems able to run our test suite

The setup documentation should be turned into a Puppet module, so that we can deploy this on lizard (and so that individual developers can reproduce this setup in a way that’s easy to keep up-to-date with future changes).

Feature Branch: puppet-tails:test/8165-run-test-suite-in-jessie

Related issues

Related to #6181 (closed)
Blocked by #6315 (closed)
Blocked by #8165 (closed)

Original created by @tails on 5683 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information