Highlights of features/bugfixes in this release:
- Agents setup.py fixes
- Add explicit keyring dependencies to constrain version
- Generate shorter hostnames on GCE and Azure
- EC2 agent support for attaching volumes as nvme devices
- Adjust GCE Agent to be able to use images outside of the caller's project.
- set version to 3.8.0
- Handle EC2 InvalidInstanceID.NotFound when terminating instances.
- Add missing parameters for agent associate_static_ip
- Add missing handle_failure method for gce agent
- Call generate_rsa_key() correctly.
- Use logger.debug instead of logger.info method
- Initial working appscale-agents from appscale-tools repo