Github user srdo commented on the issue:
https://github.com/apache/storm/pull/2378
@HeartSaVioR The exclusion isn't necessary because we set Zookeeper to
version 3.4.6 in the dependencyManagement section of the root pom. It ensures
that if any child poms depend on Zookeeper without specifying a version they'll
get 3.4.6, and if Zookeeper is included transitively it'll also be version
3.4.6.---
