rc: methods marked as AuthRequired need auth unless --rc-no-auth

Methods which can read or mutate external storage will require
authorisation - enforce this.  This can be overidden by `--rc-no-auth`.

fs/rc/internal.go

@@ -17,6 +17,16 @@ func init() {
 		Help: `
 This echoes the input parameters to the output parameters for testing
 purposes.  It can be used to check that rclone is still alive and to
+check that parameter passing is working properly.`,
+	})
+	Add(Call{
+		Path:         "rc/noopauth",
+		AuthRequired: true,
+		Fn:           rcNoop,
+		Title:        "Echo the input to the output parameters requiring auth",
+		Help: `
+This echoes the input parameters to the output parameters for testing
+purposes.  It can be used to check that rclone is still alive and to
 check that parameter passing is working properly.`,
 	})
 	Add(Call{