There are a number of things we need to ensure we can cleanly import Nighthawk into Google:

• service_main.cc needs to be able to handle IPv6 addresses. Its test, service_main_test.cc, should work with TestEnvironment::getIpVersionsForTest.
• service_test.cc and process_test.cc also need to consume from TestEnvironment::getIpVersionsForTest when forming loopback addresses.
• We need to switch Envoy import paths from overlay to external/envoy based and structurally enforce this.
• We need to eliminate the race being fixed in Service: address back to back execution race #118