fix(err): No port with depends_on

As #182 were not clear, the `depends_on` from a compose file needs, at
this time, to check the port of the dependent service. If the port is
not declared (ports or with label), we need to "fail", not to "warn.

Fixes #182

internal/generator/deployment.go

@@ -268,13 +268,12 @@ func (d *Deployment) DependsOn(to *Deployment, servicename string) error {
 	for _, container := range to.Spec.Template.Spec.Containers {
 		commands := []string{}
 		if len(container.Ports) == 0 {
-			logger.Warn("No ports found for service ",
+			logger.Fatal("No ports found for service ",
 				servicename,
 				". You should declare a port in the service or use "+
 					labels.LabelPorts+
 					" label.",
 			)
-			os.Exit(1)
 		}
 		for _, port := range container.Ports {
 			command := fmt.Sprintf("until nc -z %s %d; do\n  sleep 1;\ndone", to.Name, port.ContainerPort)