Adding format to select between normal, clean and JSON. This needs some refactor

src/speed_unit.rs

@@ -1,8 +1,9 @@
+use serde::{Deserialize, Serialize};
 use structopt::clap::arg_enum;
 
 arg_enum! {
 
-#[derive(Debug)]
+#[derive(Serialize, Deserialize, Debug, Clone, Copy)]
     pub enum SpeedUnit {
         Kmh,
         Ms,