Remove logging dependencies

[wbobeirne]

We can remove debugnyan and @uphold/request-logger in favor of just using a small custom console.log-based logger, and letting implementors of the library use the logger param to pass a logger of their choosing.

The custom logging implementation should be API compliant with bunyon to keep backwards compatbility, and make it easy to plug other logger solutions into.

[JeremyRubin]

feel free to add a dep to https://www.npmjs.com/package/@types/bunyan to give this typescript types.