Merge pull request #149 from Open-EO/0.3.1

Update CHANGELOG.md

Author: m-mohr

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).
 
-## [0.3.1]
+## [0.3.1] - 2018-11-06
 
 ### Added
 - `createProcessGraph` method to client development guidelines.
@@ -40,4 +40,4 @@ First version after proof of concept tackling many major issues. No changelog av
 Version for proof of concept. No changelog available.
 
 ## [0.0.1] - 2018-02-07
-Initial version.
+Initial version.