Change BalancesMap to BTreeMap instead of HashMap

Author: elpiel

primitives/src/balances_map.rs

@@ -1,5 +1,5 @@
-use std::collections::HashMap;
+use std::collections::BTreeMap;
 
 use crate::BigNum;
 
-pub type BalancesMap = HashMap<String, BigNum>;
+pub type BalancesMap = BTreeMap<String, BigNum>;