update CHANGELOG for 1.2.0 release

Author: ehough

CHANGELOG.md

@@ -4,7 +4,7 @@ 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]
+## [1.2.0] - 2018-09-26
 
 ### Added
 * upon successful server startup, log:
@@ -13,9 +13,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   * list of ports that should be exposed
 * improved error detection and logging
 
-### Fixed
-### Changed
-
 ## [1.1.1] - 2018-08-21
 
 ### Fixed