Details
Description
Jenkins improvements
1. Add the cassandra-website job into cassandra_job_dsl.seed.groovy (so we don't lose it next time the Jenkins master is corrupted)
2. Print the SHAs of the different git repos used during the build process. Also store them in the .head files (so the pipeline can print them out too).
3. Instead of archiving artefacts, ssh them to https://nightlies.apache.org/cassandra/
(Disk usage on agents is largely under control, but disk usage on master was the new problem. The suspicion here is the Cassandra-*-artifact's artefacts was the disk usage culprit, though we have to evidence to support it.)