Support overriding Zookeeper connector to production via env property

This will allow to run production connector (and no stub runner) without `prod` profile (e.g. under `dev`) if `microservice.production` is defined
It's good to simplify everything to 3 possible cases. On the other hand, restricting app to run only under one of the profiles in that set, removes the ability to use Spring's `@Profile` for uses other than environment definition. 

IMHO it's useful for certain cases, e.g. toggling a smaller set of functionality: `enable-jms`, `enable-xxxxx`, etc.: application could be run with `-Dspring.profiles.active=dev,enable-jms`.

That's certainly out of scope for the discussion of this PR though :). We can create a ticket to discuss it.