Draw a card for player when changing turn

[phoorichet]

When a player click Endturn in the zb game, the active player changes to the opponent. Before the opponent does any action, he'll get one card from his deck to his hand.

This task is to modify the gamestate actionEndTurn to reflect the above requirements. Currently, what actionEndTurn does is only to change the player's turn. we have to add changes so that one card in deck get moved to player' hand.

The changes should also have test cases to verify the game state after applying state function.

[phoorichet]

Game client should make a call to draw a card before playing each turn