How should we handle the erlang ref in the response from aws-erlang

[andreashasse]

Background
The result from a successful request to aws-erlang typically looks like this:
{ok, Response, {HttpStatusCode, Headers, Ref}} = .. aws_something:something(...),
The Ref can be used in the API for hackney.
We should not encourage users to call the hackney API as we want to be able to switch from hackney to something else if e.g. Hackney becomes unmaintained.

Solutions
A solution would be to implement a module in aws-erlang where we make the ref opaque and create a wrap module where we tunnel all calls to hackney that could be useful. This would us a little bit more future compatible.