Revert vendor directory to support old golang (GOPATH mode)

gomodule is still in progress to migrate for now, hence multus
team decide to keep vendor directory to support build without
gomodule.

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)
+}