chanotify should use interface{} keys

Fixes #79.

Signed-off-by: Burcu Dogan <jbd@golang.org>

supervisor/supervisor.go

@@ -50,7 +50,7 @@ func New(id, stateDir string, tasks chan *StartTask, oom bool) (*Supervisor, err
 		go func() {
 			for id := range s.notifier.Chan() {
 				e := NewEvent(OOMEventType)
-				e.ID = id
+				e.ID = id.(string)
 				s.SendEvent(e)
 			}
 		}()

supervisor/worker.go

@@ -74,7 +74,7 @@ func (w *worker) Start() {
 			if err != nil {
 				logrus.WithField("error", err).Error("containerd: notify OOM events")
 			} else {
-				w.s.notifier.Add(n, t.Container.ID())
+				w.s.notifier.Add(t.Container.ID(), n)
 			}
 		}
 		ContainerStartTimer.UpdateSince(started)