Fixes#142
### Motivation
Expose HTTP Port on ZooKeeper service so we can use Prometheus
### Modifications
Bug fix to expose HTTP port on ZooKeeper service
It remains possible to override the current release namespace by setting
the `namespace` value though this may lead to having the helm metadata
and the pulsar components in different namespaces
Fixes#66
### Motivation
Trying to deploy the chart in a namespace using the usual helm pattern fails for example
```
kubectl create ns pulsartest
helm upgrade --install pulsar -n pulsartest apache/pulsar
Error: namespaces "pulsar" not found
```
fixing that while keeping the helm metadata and the deployed objects in the same namespace requires declaring the namespace twice
```
kubectl create ns pulsartest
helm upgrade --install pulsar -n pulsartest apache/pulsar --set namespace=pulsartest
Error: namespaces "pulsar" not found
```
This is needlessly confusing for newcomers who follow the helm documentation and is contrary to helm best practices.
### Modifications
I changed the chart to use the context namespace `.Release.Namespace` by default while preserving the ability to override that by explicitly providing a namespace on the commande line, with the this modification both examples behave as expected
### Verifying this change
- [x] Make sure that the change passes the CI checks.
