Revert "- added method 'getHealth' to Player.java; used to get player's current health - TobyBallClient.java now registers Health related classes with kryo - TobyBallServer.java now registers Health related classes with kryo"

This reverts commit f2dd9edb19f50cd62234232a090f19a02ddde3cf.
Revert "- added member variable 'health' to Player.java; initialized with min value 0 and max value 5"

This reverts commit 09085e771169c4bb85f8f2442eded55ca29c71e0.