diff --git a/vendor/github.com/spf13/pflag/duration.go b/vendor/github.com/spf13/pflag/duration.go
new file mode 100644
index 0000000..e9debef
--- /dev/null
+++ b/vendor/github.com/spf13/pflag/duration.go
@@ -0,0 +1,86 @@
+package pflag
+
+import (
+	"time"
+)
+
+// -- time.Duration Value
+type durationValue time.Duration
+
+func newDurationValue(val time.Duration, p *time.Duration) *durationValue {
+	*p = val
+	return (*durationValue)(p)
+}
+
+func (d *durationValue) Set(s string) error {
+	v, err := time.ParseDuration(s)
+	*d = durationValue(v)
+	return err
+}
+
+func (d *durationValue) Type() string {
+	return "duration"
+}
+
+func (d *durationValue) String() string { return (*time.Duration)(d).String() }
+
+func durationConv(sval string) (interface{}, error) {
+	return time.ParseDuration(sval)
+}
+
+// GetDuration return the duration value of a flag with the given name
+func (f *FlagSet) GetDuration(name string) (time.Duration, error) {
+	val, err := f.getFlagType(name, "duration", durationConv)
+	if err != nil {
+		return 0, err
+	}
+	return val.(time.Duration), nil
+}
+
+// DurationVar defines a time.Duration flag with specified name, default value, and usage string.
+// The argument p points to a time.Duration variable in which to store the value of the flag.
+func (f *FlagSet) DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
+	f.VarP(newDurationValue(value, p), name, "", usage)
+}
+
+// DurationVarP is like DurationVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) DurationVarP(p *time.Duration, name, shorthand string, value time.Duration, usage string) {
+	f.VarP(newDurationValue(value, p), name, shorthand, usage)
+}
+
+// DurationVar defines a time.Duration flag with specified name, default value, and usage string.
+// The argument p points to a time.Duration variable in which to store the value of the flag.
+func DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
+	CommandLine.VarP(newDurationValue(value, p), name, "", usage)
+}
+
+// DurationVarP is like DurationVar, but accepts a shorthand letter that can be used after a single dash.
+func DurationVarP(p *time.Duration, name, shorthand string, value time.Duration, usage string) {
+	CommandLine.VarP(newDurationValue(value, p), name, shorthand, usage)
+}
+
+// Duration defines a time.Duration flag with specified name, default value, and usage string.
+// The return value is the address of a time.Duration variable that stores the value of the flag.
+func (f *FlagSet) Duration(name string, value time.Duration, usage string) *time.Duration {
+	p := new(time.Duration)
+	f.DurationVarP(p, name, "", value, usage)
+	return p
+}
+
+// DurationP is like Duration, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) DurationP(name, shorthand string, value time.Duration, usage string) *time.Duration {
+	p := new(time.Duration)
+	f.DurationVarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Duration defines a time.Duration flag with specified name, default value, and usage string.
+// The return value is the address of a time.Duration variable that stores the value of the flag.
+func Duration(name string, value time.Duration, usage string) *time.Duration {
+	return CommandLine.DurationP(name, "", value, usage)
+}
+
+// DurationP is like Duration, but accepts a shorthand letter that can be used after a single dash.
+func DurationP(name, shorthand string, value time.Duration, usage string) *time.Duration {
+	return CommandLine.DurationP(name, shorthand, value, usage)
+}