Amazon ECS CLI - Release v0.6.0

• Feature - Update ami to amzn-ami-2017.03.c-amazon-ecs-optimized
• Feature - Support cluster and region runtime flag for all ECS commands
• Feature - Support --task-role-arn in compose commands
• Feature - Support memory reservation in compose
• Feature - ecs-cli up without auto-assigned IP address
• Enhancement - Support Multiple Security Groups in the ecs-cli up
• Enhancement - Support ecs-cli compose run with multiple containers and run command overrides
• Enhancement - Support additional instance types p2, g2, and x1
• Bug - Avoid SIGSEGV error when ec2InstanceID does not exist #231
• Bug - Allow dashes “-“ in ecs-cli push #238
• Bug - Allow ecs-cli compose up to have project name longer than 36 characters #97