[20190620150317] AMI Update and Bug Fixes

[ddollar]

Notes

• Updates to the latest AMIs for ECS and EKS
• Several bug fixes around k8s-based (local and kaws) providers.

Pull Requests

• #3263 support for timers in k8s-based providers [@ddollar]
• #3264 update ecs amis and region options [@ddollar]
• #3266 add rack type label to config namespace [@ddollar]
• #3267 create new http transport to avoid concurrency issues [@ddollar]