Add changelog entry for rcmachado#77

Author: mattwynne

CHANGELOG.md

@@ -6,6 +6,8 @@ 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]
+### Added
+- `latest` command to show latest version number ([#77](https://github.com/rcmachado/changelog/pull/77))
 
 ## [0.7.0] - 2020-07-03
 ### Changed