api: add a notion of build version to Node identity. (#108)
api: add a notion of build version to Node identity. (#108)

Fixes #95.
lyft/envoy-api,lyft/envoy-api,jrajahalme/envoy-api,rshriram/envoy-api,jrajahalme/envoy-api,lyft/envoy-api,jrajahalme/envoy-api,rshriram/envoy-api,rshriram/envoy-api,jrajahalme/envoy-api