CHANGELOG.md: Version 1.2.0

This version only works with DSpace 6+ where the internal item id-
entifiers are UUIDs instead of integers. Version 1.1.1 was the last
version to work with DSpace 4 and 5.

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](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## [1.2.0] - 2020-03-02
 ## Changed
 - Remove Python 3.5 from TravisCI because black requires Python >= 3.6
 - Adapt API for DSpace 6+ UUIDs