set children_eval_method to be default in main

src/main.rs

@@ -1,5 +1,5 @@
 use game::Game;
-use logic::{ChildrenEvalMethod, FutureMoveConfig};
+use logic::FutureMoveConfig;
 use repr::Piece;
 
 mod agent;
@@ -26,7 +26,7 @@ fn main() {
             max_arena_size: 100_000_000,
             do_prune: true,
             print: true,
-            children_eval_method: ChildrenEvalMethod::AverageDivDepth,
+            children_eval_method: Default::default(),
         },
     );