fix(build): exit early in build on failure
refactor(registry): Pass stop channel through EventStream
refactor(registry): s/eventChannel/eventchan/g
chore(event): gofmt
test(registry): Add registry.pipe test
feat(registry): track last-seen index in registry.watch
fix(event): call Listen() on EventBus; use EventBus.chClose to stop
fix(EventBus): wrap EventBus.Listen() code in goroutine
fix(event): Fix log line
fix(EventBus): dereference Event before handing to listeners
Merge pull request #57 from bcwaldon/restart-watcher

registry/event.go refactoring, testing