Provide InfoContributor for EC2 and ECS

[eddumelendez]

Services running at EC2 can use Instance Data to provide information via actuator endpoint /info [1]. The same can be implemented when a service is running at ECS, ECS_CLUSTER can be found at /etc/ecs/ecs.config [2]

[1] https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-retrieval.html
[2] https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-agent-config.html