fix tests

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -
fyi, I think we are considering dropping the default Content documents in the Testing component in a future version (and indeed anything that is CMF specific). //cc @WouterJ