Debug namespace is not microservices (SOA) oriented

Express uses hardcoded values for debug namespace, for example:
https://github.com/expressjs/express/blob/b69b7605b07b41273acc931d25ab585377bcd107/lib/router/index.js#L20

and it is extremly hard to determine in output where things are happening while doing TDD on microservices architecture. It would be nice to allow to specify prefix for namespace, i.e. per microservice which is an express app.