Rajout des tests des CartesianVector et des Movable.

src/main/java/engine/Kernel.java

src/main/java/engine/graphic/GraphicEngine.java

src/main/java/engine/graphic/ImageComponent.java

src/main/java/engine/graphic/ScoreComponent.java

src/main/java/engine/physic/CartesianVector.java

src/main/java/engine/physic/Entity.java

src/main/java/engine/physic/Movable.java

src/main/java/engine/physic/NotMovable.java

src/main/java/engine/physic/PhysicEngine.java

src/main/java/pong/PongApp.java

src/main/java/pong/PongBall.java

src/main/java/pong/PongObject.java

src/main/java/pong/PongRacket.java

src/main/java/sprint2_demo/Grid.java

src/main/java/sprint2_demo/Hero.java

src/test/java/engine/physic/CartesianVectorTest.java

src/test/java/engine/physic/MovableTest.java

src/test/java/pong/PongBallTest.java