Refactor the thread initialization and ActiveRecord.with_connection blocks

Extract Method
Game Player spec
Implement "play all coin" action

GamePlayer.find_coin_in_hand implemented
Implement "amount of coin in hand"

GamePlayer.amount_of_coin_in_hand implemented
Only show "play-all-coin" button if there's coin in the player's hand, and the action isn't "play-all-coin"

GamePlayer.coin_in_hand? implemented
Adding the coin method for each coin card