Needs to be updated for new changes in the libraries:
- https://github.com/travello-gmbh/amazon-alexa-skill-library/releases/tag/2.4.0
- https://github.com/travello-gmbh/amazon-alexa-skill-zf/releases/tag/2.4.0
Release 2.3.0 was skipped to keep release numbers in line.