Simpler Case usage

[Stranger6667]

To simplify the current example we can have a method to convert Case instance into a dictionary that could be passed into requests.request.

@schema.parametrize()
def test_no_server_errors(case):
    response = requests.request(**case.as_requests(BASE_URL))
    assert response.status_code < 500

it will save some keystrokes and will make the test shorter. Also, it could be a method on the Case that will include a network call via requests or urllib:

@schema.parametrize()
def test_no_server_errors(case):
    response = case.call(BASE_URL)
    assert response.status_code < 500

[Stranger6667]

Done in 08f0971