amazon-ecs-cli: Release v1.18.0
1.18.0
Enhancement - Print verbose messages for credential chain errors (#937)
Enhancement - Add G4 instance support (#940)
Enhancement - Add more descriptive logging to integ tests (#931)
Bug - Pull correct AMI type for G3 instance types. (#940)
Bug - Send optional fields as nil instead of "" to ECS (#938)
Bug - ecs-cli local up can now read from parameter store when forward slashes exist in parameter name (#935)