Added license and changelog

CHANGELOG.md

+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## [0.1.0] - 2019-03-14
+### Added
+- Initial release of Hecaton
+
+[Unreleased]: https://github.com/olivierlacan/keep-a-changelog/compare/v0.0.1...HEAD
+[0.1.1]: https://github.com/olivierlacan/keep-a-changelog/compare/v0.1.0...v0.1.1
+[0.1.0]: https://github.com/olivierlacan/keep-a-changelog/releases/tag/v0.1.0
+