Fix traces left in zookeeper

We currently are leaving the root node in zookeeper
whenever this test is ran, we should instead be removing
the full directory and any children to avoid leaving
test data behind in zookeeper (aka, cleanup our dirty
laundry).

Fixes bug 1330807

Change-Id: I56d9dabd9926463506e1710ddf0a6c4831d5dc57
Merge "Fix traces left in zookeeper"