vcr_config fixture doesn't filter DELETE request

[gegnew]

It's possible that I've done something wrong, but I've overridden the vcr config in conftest.py as below:

@pytest.fixture(scope='module')
def vcr_config():
    """Pytest hook for vcr config"""
    return {
        'filter_headers': ['Cookie'],
        'before_record_response': scrub_header('set-cookie',
                                               repl='safetoken'),
        'cassette_library_dir': 'tests/cassettes'
                        }

Where scrub_header replaces headers as such:

def scrub_header(string, repl=''):
    """Remove secrets from stored vcr cassettes"""
    def before_record_response(response):
        response['headers'][string] = repl
        return response
    return before_record_response

This works great for every other request method (works for GET, POST, PATCH, PUT), but those headers are not removed before the delete request .yaml is saved.

Note that headers are removed by two methods:

1. 'filter_headers' is passed to vcr to remove "Cookie"
2. the 'set-cookie' header is replaced with 'safetoken' in before_record_response
   Interestingly, neither of these methods works for the delete request.

Thoughts?