refactor tests and delete check_cloudside.py

[austinorr]

the existence of check_cloudside.py is a bit of a wart since it does nothing we can't do with pure pytest and it creates the need for all this complexity in the test init file here.

we should delete both. since custom test running kwargs are natively supported in pytest by the following pattern:

@pytest.fixture(scope="session")
def some_option(request):
    return request.config.getoption("--some_option", False)

and then use it like a regular fixture wherever it's needed by pytest.

the init file should be emptied, the check_cloudside.py file should be deleted, and the package init file should not import anything from tests at all.

[austinorr]

@phobson any thoughts on this? Is this a pattern that is worth maintaining?