Added ZooKeeperProcessRegistry 

From now on process registry can read properties from ZooKeeper paths!

Just add curator to your Spring Boot classpath and enjoy ZooKeeper values injected into your application:

    // Read value from ZK /service/invoicing/url path
    @Value("service.invoicing.url");
    String invoicingMicroserviceUrl;
    
    Invoice invoice = new RestTemplate().getForObject(invoicingMicroserviceUrl, Invoice.class);

If Fabric8/ZooKeeper is down, the Spring Boot application will fallback to standard Spring property sources (like `application.properties` file or system properties).