fix: header redaction

[sidakram]

Redacted certain headers in req/res headers object.
Request headers redacted -

    'cookie',
    'referer',
    'location',
    'geolocation',
    'authorization',
    'x-real-ip',
    'user-agent',
    'x-forwarded-for',
    'proxy-authorization'

Response headers redacted -

    'location',
    'x-real-ip',
    'x-forwarded-for'

targets: #155

[jsumners]

Thank you for working on this. I think we should omit the headers completely. If someone wants to include them with redaction, and incur the associated cost, they should be able to provide their own serializers.