Update to Docker 1.11.1 and Docker Compose 1.7.0
Update to Docker 1.11.1 and Docker Compose 1.7.0

holmesjr/elastic-ci-stack-for-aws,holmesjr/elastic-ci-stack-for-aws,caremonkey/buildkite-aws-elastic-stack,caremonkey/buildkite-aws-elastic-stack,buildkite/elastic-ci-stack-for-aws