Should etnservice support credential caching?

[PietrH]

Every OpenCPU session should have it's own R Session/Instance, thus caching credentials within a session does little harm.

However, credentials should be passed with every request from the client, thus there is little advantage in caching the credentials object.

Currently the function get_credentials() fetches credentials from the Sys env.

• Where is this function used?
• Should it be removed?