Generate LB sandbox/endpoint names in one place
Generate LB sandbox/endpoint names in one place

Signed-off-by: Chris Telfer <9cf1a5ba8f085fe3bf87fd3e4704febafc338899@docker.com>

vdemeester/libnetwork,vdemeester/libnetwork,mahak/libnetwork,docker/libnetwork,medallia/libnetwork,mahak/libnetwork,medallia/libnetwork,docker/libnetwork,vdemeester/libnetwork,mahak/libnetwork,medallia/libnetwork,docker/libnetwork