bumping zk version to 3.4.5-2

The current zookeeper version references
http://apache.mirrors.tds.net/zookeeper/zookeeper-3.4.3/zookeeper-3.4.3.tar.gz which is a 404

> zookeeper@3.4.1-2 install /Users/nachikettorwekar/test-repo/node-zk-ultralight/node_modules/zookeeper
> node-gyp rebuild
ACTION binding_gyp_libzk_target_build_zk_client_lib .
Downloading zookeeper-3.4.3 from http://apache.mirrors.tds.net/zookeeper/zookeeper-3.4.3/zookeeper-3.4.3.tar.gz
tar: Unrecognized archive format

Updating to latest zk version - 3.4.5-2 , solves this issue.