Update Changelog for v3.0.0-rc1

CHANGELOG.md

@@ -4,6 +4,19 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [v3.0.0-rc1](https://github.com/buildkite/elastic-ci-stack-for-aws/tree/v3.0.0-rc1) (2018-04-18)
+[Full Changelog](https://github.com/buildkite/agent/compare/v2.3.5...v3.0.0-rc1)
+
+### Changed
+- Use new Metrics API, drop requirement for org-slug and api-token [#405](https://github.com/buildkite/elastic-ci-stack-for-aws/pull/405) (@lox)
+- Bump Lifecycled to v2.0.0 [#404](https://github.com/buildkite/elastic-ci-stack-for-aws/pull/404) (@lox)
+- Add support for billing tags [#398](https://github.com/buildkite/elastic-ci-stack-for-aws/pull/398) (@tduffield)
+- Drop support for buildkite-agent v2, stable is 3.0.0 [#400](https://github.com/buildkite/elastic-ci-stack-for-aws/pull/400) (@lox)
+- Don't blow up when no plugins are enabled [#394](https://github.com/buildkite/elastic-ci-stack-for-aws/pull/394) (@haines)
+- Fail install if docker hasn't started [#387](https://github.com/buildkite/elastic-ci-stack-for-aws/pull/387) (@lox)
+- Update docker to stable 17.12.1-ce [#391](https://github.com/buildkite/elastic-ci-stack-for-aws/pull/391) (@lox)
+
+
 ## v2.3.5 - 2018-02-26
 ### Changed
 - Make EnableDockerUserNamespaceRemap the new default [\#378](https://github.com/buildkite/elastic-ci-stack-for-aws/issues/378)