Add tests (#5)

Reviewed-on: #5

src/main.rs

@@ -23,7 +23,7 @@ async fn main() {
     match prsr.file_dump().await {
         Ok(contacts) => {
             prsr.print_phone_numbers(&contacts);
-            prsr.save_file(contacts).await;
+            prsr.save_file(contacts, parser::DEFAULT_OUTPUT_FILE).await;
         }
         Err(err) => {
             eprintln!("Error: {err:?}");