remove some unnecessary imports and call them inline

src/room.rs

@@ -1,4 +1,4 @@
-use crate::{Exit, ExitInstance, Instance, mock, Position, from_base36, ToBase36, optional_data_line};
+use crate::{Exit, ExitInstance, Instance, Position, from_base36, ToBase36, optional_data_line};
 
 #[derive(Debug, Eq, PartialEq)]
 pub struct Room {
@@ -88,7 +88,7 @@ impl From<String> for Room {
 fn test_room_from_string() {
     assert_eq!(
         Room::from(include_str!("test-resources/room").to_string()),
-        mock::room()
+        crate::mock::room()
     );
 }
 
@@ -146,5 +146,5 @@ impl ToString for Room {
 
 #[test]
 fn test_room_to_string() {
-    assert_eq!(mock::room().to_string(), include_str!("test-resources/room").to_string());
+    assert_eq!(crate::mock::room().to_string(), include_str!("test-resources/room").to_string());
 }