Implemented a few basic tests and ideas for future ones

src/infrastructure/node.zig

@@ -40,4 +40,10 @@ pub const Node = struct {
 
         try self.roads.append(allocator, road_to_add);
     }
-};
+};
+
+// TODO tests
+// road reference test
+// pos within node test
+// deinit test
+// roads ptr list test