run 'go get -u; make revendor'

Signed-off-by: Stephan Renatus <srenatus@chef.io>

vendor/github.com/jonboulle/clockwork/clockwork.go

@@ -11,7 +11,6 @@ type Clock interface {
 	After(d time.Duration) <-chan time.Time
 	Sleep(d time.Duration)
 	Now() time.Time
-	Since(t time.Time) time.Duration
 }
 
 // FakeClock provides an interface for a clock which can be
@@ -61,10 +60,6 @@ func (rc *realClock) Now() time.Time {
 	return time.Now()
 }
 
-func (rc *realClock) Since(t time.Time) time.Duration {
-	return rc.Now().Sub(t)
-}
-
 type fakeClock struct {
 	sleepers []*sleeper
 	blockers []*blocker
@@ -135,11 +130,6 @@ func (fc *fakeClock) Now() time.Time {
 	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)
-}
-
 // 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) {