Skip failing test

One of the tests in module `tests.foreman.api.test_contentviews` fails with a
message stating 'System record should be implemented'.

* Systems can now be created via the "new" API layer.
* An existing smoke test does exactly what the failing test is supposed to do.

Stub out this broken test, preventing it from running and failing.
Merge pull request #1288 from Ichimonji10/jenkins

Skip failing test