private DeployTester createTester(List<Host> hosts, List<ModelFactory> modelFactories, Zone zone) {
        return createTester(hosts, modelFactories, zone, Clock.systemUTC());
    }
Create the given number of hosts using the supplied versions--the last version is repeated as needed.
configserver/src/test/java/com/yahoo/vespa/config/server/deploy/HostedDeployTest.java