docs: Sets the changelog latest version to 0.3.0

Author: ironcev

CHANGELOG.md

@@ -3,7 +3,7 @@ All notable changes to the "Without Guns" extension will be documented in this f
 
 The format of the file is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
-## [Unreleased] 
+## [0.3.0] - 2017-10-14
 ### Added
 - "Guns: With" and "Guns: Without" commands are context sensitive. (They are active only if the Guns are currently taken or not, respectively.)