Improvements and fixes to Jenkinsfile
 - Fix slack changelog message. currentBuild.changeSets is an array and has to first be formatted.
 - Remove cassandra-build directory in Summary stage, so 'Restart from Stage' builds work,
 - Archive the cassandra-test-report.txt artifact
 - Add StabilityTestDataPublisher to the pipeline junit results (provides flakey info)

 patch by Mick Semb Wever; reviewed by Berenguer Blasi for CASSANDRA-15875
1 file changed