Add String to Runtime interface

runtime/runtime.go

@@ -17,6 +17,8 @@ var (
 
 // Runtime is a service runtime manager
 type Runtime interface {
+	// String describes runtime
+	String() string
 	// Init initializes runtime
 	Init(...Option) error
 	// Create registers a service

runtime/service.go

@@ -170,6 +170,8 @@ func (s *service) Wait() {
 		s.Metadata["status"] = "error"
 		s.Metadata["error"] = err.Error()
 		s.err = err
+	} else {
+		s.Metadata["status"] = "done"
 	}
 
 	// no longer running