upgraded vendored jwt-go lib

vendor/github.com/dgrijalva/jwt-go/cmd/jwt/args.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+)
+
+type ArgList map[string]string
+
+func (l ArgList) String() string {
+	data, _ := json.Marshal(l)
+	return string(data)
+}
+
+func (l ArgList) Set(arg string) error {
+	parts := strings.SplitN(arg, "=", 2)
+	if len(parts) != 2 {
+		return fmt.Errorf("Invalid argument '%v'.  Must use format 'key=value'. %v", arg, parts)
+	}
+	l[parts[0]] = parts[1]
+	return nil
+}