remove unused import

src/main.rs

@@ -1,5 +1,3 @@
-use std::collections::HashMap;
-
 const IMAGE_DIMENSION_SD: usize = 8;
 const IMAGE_DIMENSION_HD: usize = 16;
 
@@ -574,6 +572,7 @@ fn sprite_to_string(sprite: Sprite) -> String {
 
 #[test]
 fn test_sprite_to_string() {
+    // todo this fails
     let output = sprite_to_string(test_sprite());
     let expected = "SPR a\n00000000\n01111000\n01001000\n00111100\n00111100\n01011110\n01011110\n01101111\nNAME hatch\nDLG SPR_0\nPOS 4 9,7".to_string();