convert int IDs to strings

src/palette.rs

@@ -1,9 +1,8 @@
 use crate::colour::Colour;
-use crate::{from_base36, ToBase36};
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct Palette {
-    pub id: u64,
+    pub id: String,
     pub name: Option<String>,
     pub colours: Vec<Colour>,
 }
@@ -13,7 +12,7 @@ impl From<String> for Palette {
     fn from(string: String) -> Palette {
         let lines: Vec<&str> = string.lines().collect();
 
-        let id = from_base36(&lines[0].replace("PAL ", ""));
+        let id = lines[0].replace("PAL ", "");
 
         let name = match lines[1].starts_with("NAME") {
             true => Some(lines[1].replace("NAME ", "").to_string()),
@@ -46,7 +45,7 @@ impl ToString for Palette {
         }
         colours.pop();
 
-        format!("PAL {}\n{}{}", self.id.to_base36(), name, colours)
+        format!("PAL {}\n{}{}", self.id, name, colours)
     }
 }
 
@@ -60,7 +59,7 @@ mod test {
         let output = Palette::from("PAL 1\nNAME lamplight\n45,45,59\n66,60,39\n140,94,1".to_string());
 
         let expected = Palette {
-            id: 1,
+            id: "1".to_string(),
             name: Some("lamplight".to_string()),
             colours: vec![
                 Colour {
@@ -89,7 +88,7 @@ mod test {
         let output = Palette::from("PAL 9\n45,45,59\n66,60,39\n140,94,1".to_string());
 
         let expected = Palette {
-            id: 9,
+            id: "9".to_string(),
             name: None,
             colours: vec![
                 Colour {
@@ -116,7 +115,7 @@ mod test {
     #[test]
     fn test_palette_to_string() {
         let output = Palette {
-            id: 16,
+            id: "g".to_string(),
             name: Some("moss".to_string()),
             colours: vec![
                 Colour {