Re-set version to UNRELEASED.

.config

@@ -1,5 +1,5 @@
 # Isabelle/DOF Version Information
-DOF_VERSION="1.0.0"    
+DOF_VERSION="Unreleased"    # "Unreleased" for development, semantic version for releases 
 DOF_LATEST_VERSION="1.0.0"    
 DOF_LATEST_ISABELLE="Isabelle2019"    
 DOF_LATEST_DOI="10.5281/zenodo.3370483"

CHANGELOG.md

@@ -5,6 +5,12 @@ 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]
+
+### Added
+
+### Changed
+
 ## 1.0.0 - 2018-08-18
 
 ### Added