Attempt to clarify the structure of our tests. Each test case is now
encapsulated in a script in `test/cases`. Each of these scripts should
be runnable on a pristine machine and be independent of each other. It
is up to the test-orchestractor to decide if they should be run
consequtively instance, or in parallel on separate instances. Each
script can execute several tests and call whatever helper binaries
is desired. However, each case should be assumed to always run as one.
In case the job fails completely, resources might leak. This patch
together with the one introducing predictable names for CI artifacts
will make sure we wipe all resources after each CI run.
