Update release process documentation wrt bintray removal and new usage of ASF JFrog Artifactory  ref: https://github.com/apache/cassandra/pull/985
Update release process documentation wrt bintray removal and new usage of ASF JFrog Artifactory
 ref: https://github.com/apache/cassandra/pull/985

 patch by Mick Semb Wever; reviewed by Ekaterina Dimitrova

thelastpickle/cassandra,belliottsmith/cassandra,pauloricardomg/cassandra,thelastpickle/cassandra,adelapena/cassandra,belliottsmith/cassandra,mshuler/cassandra,mshuler/cassandra,adelapena/cassandra,szhou1234/cassandra,driftx/cassandra,blambov/cassandra,blambov/cassandra,driftx/cassandra,mshuler/cassandra,adelapena/cassandra,driftx/cassandra,jrwest/cassandra,driftx/cassandra,mike-tr-adamson/cassandra,pauloricardomg/cassandra,belliottsmith/cassandra,tjake/cassandra,instaclustr/cassandra,tjake/cassandra,pauloricardomg/cassandra,instaclustr/cassandra,apache/cassandra,instaclustr/cassandra,jrwest/cassandra,jrwest/cassandra,tjake/cassandra,apache/cassandra,apache/cassandra,mshuler/cassandra,jrwest/cassandra,szhou1234/cassandra,blambov/cassandra,szhou1234/cassandra,pauloricardomg/cassandra,thelastpickle/cassandra,mike-tr-adamson/cassandra,mike-tr-adamson/cassandra,szhou1234/cassandra,belliottsmith/cassandra,adelapena/cassandra,apache/cassandra,blambov/cassandra,thelastpickle/cassandra,tjake/cassandra,mike-tr-adamson/cassandra,instaclustr/cassandra