added test, idle afte goal reached

tests/ai_test.rs

@@ -0,0 +1,32 @@
+use antf::lib::screen::init_screen;
+use antf::lib::point::Point;
+use antf::lib::ai::AIGoal;
+use antf::lib::world::{World, simulate, render};
+use antf::lib::entity::{Entities, Ant};
+
+use ncurses::*;
+use std::thread::sleep;
+use std::time;
+
+#[test]
+fn test_astar() {
+    let mut board = init_screen(); 
+    let mut world = World::new();
+
+    let mut entities = Entities::new();
+    let id = entities.add_ant(0,0);
+
+    let a = entities.data.get_mut(&id).unwrap();
+    let ant: &mut Ant = a.downcast_mut::<Ant>().unwrap(); 
+    ant.goal = AIGoal::Reach(Point(10,10));
+
+    for _ in 0..60 {
+        // TODO: add way to break out of the loop by hitting a random key
+        simulate(&mut entities, &mut world, &mut board);
+        render(&entities, &world, &board);
+        sleep(time::Duration::from_millis(100));
+        refresh();
+    }
+    endwin();
+}
+