Register all marathon apps in consul

[tsaridas]

I would actually like to have all services in marathon added to consul but I see the MARATHON_CONSUL_LABEL value is constant and there is no configuration for it.

[janisz]

Hi @tsaridas

It's good idea to make MARATHON_CONSUL_LABEL configurable and add possibility to register all services (e.g. provided config value is empty). Changes are required in AppId.ConsulServiceName and Config.

This issue is related to #81 and could be resolved in same way — MARATHON_CONSUL_LABEL could be provided as a parameter or as a global variable that will be setup at the beginning of main.

[janisz]

@tsaridas I think your problem is not related to MARATHON_CONSUL_LABEL. In my opinion it should stay as is. We could add another configuration option to say all services should be registered in Consul. If we add special meaning for empty string in MARTHON_CONSUL_LABEL we will lose ability to change names for single service.