Update Changelog

CHANGELOG.rst

 Unreleased changes
 ------------------
 
-* None
+* Python environment is not version tracked until now
 
 
 Version 0
 ---------
 
-0.2.0 / 2020-02-08
+0.4.0 / 2020-11-09
 ~~~~~~~~~~~~~~~~~~
-* Initial commit
+* Docker: Resized pyhtia/jetset output particle vector
+
+0.3.0 / 2020-09-05
+~~~~~~~~~~~~~~~~~~
+* Docker: Fixed environment variables 
+
+0.2.0 / 2020-09-03
+~~~~~~~~~~~~~~~~~~
+* Docker: GiBUU compiled with RootTuple for root file output
+
+0.1.0 / 2020-01-21
+~~~~~~~~~~~~~~~~~~
+* Docker: First GiBUU docker environment