We can't assume the existence of a parent or that the parent has a `moved` event.

This is an interesting problem. We need to add some functionality to the app to check for pickups as the rover moves. One way to do that would be to have the grid have references to what is on it and where. This would also be part of the solution for adding an object to a specific grid space without having to manually match the grid location with the physical location of the object.

If we had a more robust `grid` component with a method `addToGrid` that had a parameter `gridCoord` ( x, y ), we could then calculate the translation of that object and place it there. We could then have something like `grid.checkGrid( gridCoord )` that would return a list of what is at that coordinate. If there is an `inventoriable` object there, then the rover might pick it up, some other objects it may ignore, etc.

@eric79 @kadst43 @ajiraffe Thoughts? Concerns? Questions?

By the way, this would probably not pile on to your task, Adam. I don't want this task to get any more complicated.