Prototype a simple service gateway

[xcoulon]

Evaluate how https://github.com/hellofresh/janus can help building a minimal service proxy with routing capabilities.

Eg:

• requests to https://api.openshift.io/api/auth/* are forwarded internally to http://auth/api/*
• requests to https://api.openshift.io/api/wit/* are forwarded internally to http://core/api/*

The service should also provide the usual /api/status and /api/metrics endpoints.

The routing should be configured in a yaml/json file can be deployed/managed with a ConfigMap on OpenShift.

The service can be bootstrapped using https://github.com/fabric8-services/fabric8-starter to reuse some packages from https://github.com/fabric8-services/fabric8-common, but here, Goa may not be needed (the /api/status endpoint could be handled with a simpler net/http handler)