Similar to the instanceRole problem with database, registry doesn't seem to like instanceRoles

[jwalters-gpsw]

Similar to the instanceRole problem with database, registry doesn't seem to like AWS instanceRoles. The create_bucket script was failing with the empty creds. Maybe the real issue is the env is set when it shouldn't be.

Watching this possible upstream problem:

distribution/distribution-library-image#47

ECS also uses instanceRoles for their "tasks".

[kingdonb]

I've opened teamhephy/registry#3 to check if this is still an issue, and hopefully there are upstream changes we should pull to resolve it.