set version number in changelog

Author: deargle

CHANGELOG.md

@@ -4,7 +4,6 @@ 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]
 ### Changed
 - Drop support for python2