diff --git a/vendor/github.com/golang/protobuf/ptypes/duration.go b/vendor/github.com/golang/protobuf/ptypes/duration.go
new file mode 100644
index 0000000..b2b55dd
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/ptypes/duration.go
@@ -0,0 +1,76 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ptypes
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	durationpb "github.com/golang/protobuf/ptypes/duration"
+)
+
+// Range of google.protobuf.Duration as specified in duration.proto.
+// This is about 10,000 years in seconds.
+const (
+	maxSeconds = int64(10000 * 365.25 * 24 * 60 * 60)
+	minSeconds = -maxSeconds
+)
+
+// Duration converts a durationpb.Duration to a time.Duration.
+// Duration returns an error if dur is invalid or overflows a time.Duration.
+//
+// Deprecated: Call the dur.AsDuration and dur.CheckValid methods instead.
+func Duration(dur *durationpb.Duration) (time.Duration, error) {
+	if err := validateDuration(dur); err != nil {
+		return 0, err
+	}
+	d := time.Duration(dur.Seconds) * time.Second
+	if int64(d/time.Second) != dur.Seconds {
+		return 0, fmt.Errorf("duration: %v is out of range for time.Duration", dur)
+	}
+	if dur.Nanos != 0 {
+		d += time.Duration(dur.Nanos) * time.Nanosecond
+		if (d < 0) != (dur.Nanos < 0) {
+			return 0, fmt.Errorf("duration: %v is out of range for time.Duration", dur)
+		}
+	}
+	return d, nil
+}
+
+// DurationProto converts a time.Duration to a durationpb.Duration.
+//
+// Deprecated: Call the durationpb.New function instead.
+func DurationProto(d time.Duration) *durationpb.Duration {
+	nanos := d.Nanoseconds()
+	secs := nanos / 1e9
+	nanos -= secs * 1e9
+	return &durationpb.Duration{
+		Seconds: int64(secs),
+		Nanos:   int32(nanos),
+	}
+}
+
+// validateDuration determines whether the durationpb.Duration is valid
+// according to the definition in google/protobuf/duration.proto.
+// A valid durpb.Duration may still be too large to fit into a time.Duration
+// Note that the range of durationpb.Duration is about 10,000 years,
+// while the range of time.Duration is about 290 years.
+func validateDuration(dur *durationpb.Duration) error {
+	if dur == nil {
+		return errors.New("duration: nil Duration")
+	}
+	if dur.Seconds < minSeconds || dur.Seconds > maxSeconds {
+		return fmt.Errorf("duration: %v: seconds out of range", dur)
+	}
+	if dur.Nanos <= -1e9 || dur.Nanos >= 1e9 {
+		return fmt.Errorf("duration: %v: nanos out of range", dur)
+	}
+	// Seconds and Nanos must have the same sign, unless d.Nanos is zero.
+	if (dur.Seconds < 0 && dur.Nanos > 0) || (dur.Seconds > 0 && dur.Nanos < 0) {
+		return fmt.Errorf("duration: %v: seconds and nanos have different signs", dur)
+	}
+	return nil
+}