repository tests using apis
Do not check content-type of HTTP 204 messages

Checking the content-type of an HTTP 204 message does not make sense, as HTTP
204 messages "MUST NOT include a message-body". Make the test suite reflect this
fact.
Merge pull request #1274 from sghai/repo-api

repository tests using apis
Merge pull request #1286 from Ichimonji10/http-204

Do not check content-type of HTTP 204 messages
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.