message: A*: use Index to unwrap the score lookup
diff: @@ -93,7 +93,7 @@ pub fn astar<G, F, H, K, IsGoal>(graph: G, start: G::NodeId, mut is_goal: IsGoal
  // This lookup can be unwrapped without fear of panic since the node was necessarily scored
  // before adding him to `visit_next`.
  - let node_score = *scores.get(&node).unwrap();
  + let node_score = scores[&node];
  for edge in graph.edges(node) {
  let next = edge.target();
  