Create gameover scene

[davcri]

We want to create a GameOver scene that should be displayed on gameover.

This scene should contain:

1. The current score of the player
2. ~~A button (that will be used in another issue to restart the game)~~ Done in master branch

In the future it would be nice to have players insert their name when finishing the game (like old arcade games).

[javieracevedo]

I wanna try this one.

[davcri]

@javieracevedo I updated the description, someone already pushed some code to the master branch, check it out!

[Thomazino]

I want to contribute on this one too plz

[davcri]

Sure @Thomazino! Keep in mind that we already have a GameOver scene, so we just need the score to be displayed!

Feel free to ask any question if you need clarification!