Fix ZooKeeper dist path
Currently the ZooKeeper jar and the rest of the ZK dist files are
installed to the wrong path:
```
test@debian:~/vitess$ ls -l dist/vt-zookeeper-3.8.0/vt-zookeeper-3.8.0/lib/
total 15876
-rw-r--r-- 1 test test 16255350 Aug 3 14:39 zookeeper-3.8.0-fatjar.jar
```
The jar should install to `dist/vt-zookeeper-3.8.0/lib/`. This patch fixes.
With patch applied:
```
test@debian:~/vitess$ ls -l dist/vt-zookeeper-3.8.0/lib/
total 15876
-rw-r--r-- 1 test test 16255350 Aug 3 14:41 zookeeper-3.8.0-fatjar.jar
```
Signed-off-by: Adam Saponara <[email protected]>
