[VOL-4290] Voltha go library updates for gRPC migration

Change-Id: I1aa2774beb6b7ed7419bc45aeb53fcae8a8ecda0
diff --git a/vendor/github.com/jonboulle/clockwork/clockwork.go b/vendor/github.com/jonboulle/clockwork/clockwork.go
index 9ec96ed..1018051 100644
--- a/vendor/github.com/jonboulle/clockwork/clockwork.go
+++ b/vendor/github.com/jonboulle/clockwork/clockwork.go
@@ -11,6 +11,8 @@
 	After(d time.Duration) <-chan time.Time
 	Sleep(d time.Duration)
 	Now() time.Time
+	Since(t time.Time) time.Duration
+	NewTicker(d time.Duration) Ticker
 }
 
 // FakeClock provides an interface for a clock which can be
@@ -60,6 +62,14 @@
 	return time.Now()
 }
 
+func (rc *realClock) Since(t time.Time) time.Duration {
+	return rc.Now().Sub(t)
+}
+
+func (rc *realClock) NewTicker(d time.Duration) Ticker {
+	return &realTicker{time.NewTicker(d)}
+}
+
 type fakeClock struct {
 	sleepers []*sleeper
 	blockers []*blocker
@@ -87,7 +97,7 @@
 	defer fc.l.Unlock()
 	now := fc.time
 	done := make(chan time.Time, 1)
-	if d.Nanoseconds() == 0 {
+	if d.Nanoseconds() <= 0 {
 		// special case - trigger immediately
 		done <- now
 	} else {
@@ -130,6 +140,22 @@
 	return t
 }
 
+// Since returns the duration that has passed since the given time on the fakeClock
+func (fc *fakeClock) Since(t time.Time) time.Duration {
+	return fc.Now().Sub(t)
+}
+
+func (fc *fakeClock) NewTicker(d time.Duration) Ticker {
+	ft := &fakeTicker{
+		c:      make(chan time.Time, 1),
+		stop:   make(chan bool, 1),
+		clock:  fc,
+		period: d,
+	}
+	ft.runTickThread()
+	return ft
+}
+
 // Advance advances fakeClock to a new point in time, ensuring channels from any
 // previous invocations of After are notified appropriately before returning
 func (fc *fakeClock) Advance(d time.Duration) {