implement a version 3 test

[rikedyp]

We probably do want the ability to tie specific tests to specific tasks in exercises. This will require a little design work to determine how to attach the meta data of task_id to tests within a single file.

[rikedyp]

Ideas to check out:

• single .aplf file with comments denoting test_id
• namespace for each test with a test_id scalar number
• maybe a label for each test_id?

[ErikSchierboom]

FYI it's perfectly fine to launch with a v1 test runners. Most tracks do