[CHANGELOG] Add latest changes

Author: mpsonntag

CHANGELOG.md

@@ -3,13 +3,20 @@
 Used to document all changes from previous releases and collect changes 
 until the next release.
 
-# Latest
 
-# Dropping Python 2 support
+# Version 1.5.2
+
+## Pinning rdflib version to 5.0.0 until further notice
+
+Due to major breaking changes introduced in the upgrade of
+rdflib 5.0.0 to 6.0.0, the rdflib version is pinned to 5.0.0
+until the breaking code has been fixed.
+
+## Dropping Python 2 support
 
 Python 2 has reached end of life. The codebase has been cleaned from Python 2 and Python 3 compatible code, all tests now run exclusively on Python 3 versions.
 
-# Features
+## Features
 - `odml.save` and `odmlparser.ODMLWriter` now support additional keywords. See issue #402 and PR #403 for details.