README and Zenodo updates

Updates do the README.md file:

• The reference for the CERN-SSO-integration should be in lower case - cern-sso-integration - so that the redirect works correctly.
• Updated the link for the PaaS documentation.

Added a configuration file for Zenodo with the author names, affiliation and respective ORCID iD. This way, every time a new version is released we guarantee the correct format of the author list.