Update tests to compile again.

src/parser/util.rs

@@ -206,18 +206,3 @@ pub fn not_yet_implemented() -> Res<OrgSource<'static>, ()> {
         "Not implemented yet.".into(),
     ))));
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn get_one_before_unicode() {
-        let input = "🧡💛💚💙💜";
-        let (green_heart_index, _) = input.char_indices().skip(2).next().unwrap();
-        let starting_with_green_heart = &input[green_heart_index..];
-        let yellow_heart = get_one_before(input, starting_with_green_heart).unwrap();
-        assert!(is_slice_of(input, yellow_heart));
-        assert_eq!(yellow_heart, "💛");
-    }
-}