This diff adds in puppet manifest for Keycloak:
- the definition of the `SoftwareHeritage` realm
- the definition of the `swh-web` client in that realm
I managed to test locally with docker by hacking on [[ https://github.com/puppetlabs/pupperware | pupperware ]] and using a docker image with
`systemd` support (inspired by [[ https://github.com/solita/docker-systemd/tree/bionic | docker-systemd ]]) to run the puppet agent.
Everything works as expected regarding authentication and authorization in `swh-web`.
Nevertheless, [[ `https://github.com/treydock/puppet-module-keycloak` || puppet module for Keycloak ]] needs to upgraded to its latest version (`6.10`).
Related to T1927