Bugfix/nicolas more fixes (#36)

* FIX: Remove the serde_json depndendency

* UPDATE: Use binary representation also for languages and locales

base/src/expressions/token.rs

@@ -2,7 +2,6 @@ use std::fmt;
 
 use bitcode::{Decode, Encode};
 use serde::{Deserialize, Serialize};
-use serde_repr::{Deserialize_repr, Serialize_repr};
 
 use crate::language::Language;
 
@@ -81,8 +80,7 @@ impl fmt::Display for OpProduct {
 ///  * "#ERROR!" means there was an error processing the formula (for instance "=A1+")
 ///  * "#N/IMPL!" means the formula or feature in Excel but has not been implemented in IronCalc
 /// Note that they are serialized/deserialized by index
-#[derive(Serialize_repr, Deserialize_repr, Encode, Decode, Debug, PartialEq, Eq, Clone)]
-#[repr(u8)]
+#[derive(Serialize, Deserialize, Encode, Decode, Debug, PartialEq, Eq, Clone)]
 pub enum Error {
     REF,
     NAME,