Visual changes

src/data_provider/sqlite.rs

@@ -17,7 +17,7 @@ pub fn create_db() {
     }
 }
 
-fn ensure_db_schema(conn: &Connection) {}
+fn ensure_db_schema(_: &Connection) {}
 
 fn create_tables(conn: &Connection) {
     make_card_set(conn).unwrap();