WARNING!!! We forgot to update the `README.md` when releasing 4.0.0

[patricekrakow]

The README.md still points to the version 3.0.0 and the new API endpoints have not been added.

[larsolofsson]

ReadME.md is updated on the hotfix branch and points to verion 4.0.0, See issue #265
CWG decided to merge supporting documents to branch master at the next meeting.