Correctly size zone colliders so they connect with neighbors.

src/map.rs

@@ -215,7 +215,10 @@ fn spawn_colliders<D: 'static + Clone + Default + Send + Sync>(
                 }
             }
             for room in &map.rooms {
-                let shape = Collider::cuboid((room.width() / 2) as f32, (room.height() / 2) as f32);
+                let shape = Collider::cuboid(
+                    (room.width() / 2) as f32 + 0.5,
+                    (room.height() / 2) as f32 + 0.5,
+                );
                 let position =
                     Isometry2::new(Vector2::new(room.center().x(), room.center().y()), 0.);
                 let aabb = shape.raw.compute_aabb(&position);