Updating changelog

CHANGELOG.md

 Upcoming version:
 ------------------
+  - fixing problems in changelog generation (again) (Nikolaus Krismer)
   - Merge branch 'master' of git@dbis-git.uibk.ac.at:krismer/isochrone-vm.git (Nikolaus Krismer)
   - calling grgit add before grgit commit (by now push is empty) (Nikolaus Krismer)
   - not commiting changelogs in jenkins without changes :-) (Nikolaus Krismer)