Add release notes

CHANGELOG.md

@@ -1,35 +1,56 @@
 # Changelog
+
 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).
 
+## [Unreleased] - ReleaseDate
+
+### Changed
+
+- build system based on Nix now
+
 ## [0.3.0] - 2019-05-04
+
 ### Added
+
 - Support for passphrases
 
 ## [0.2.7] - 2018-12-23
+
 ### Added
+
 - Password strength tests
 
 ## [0.2.3] - 2018-08-17
+
 ### Fixed
+
 - Code coverage reports stuck at 100%
 
 ## [0.2.2] - 2018-08-17
+
 ### Fixed
+
 - README main TODO list
 
 ### Changed
+
 - Dependencies update
 
 ## [0.2.1] - 2018-05-26
+
 ### Fixed
+
 - Usage text in README
 
 ## [0.2.0] - 2018-05-26
+
 ### Added
+
 - Support for special characters in passwords. Thank you @apiraino
 
 ### Changed
+
 - Maintenance status on cargo to 'passively-maintained'