Extract Method: updateTheBalance(List<Transaction> transactions) from  updateBalance().
Move Method: Moved  updateBalance(long,Account) from AccountImpl to TransactionImpl.
Extract Method: From updateBalance(long balance, Account account) created 4 new different methods named updateDestinationAccountBalance(), updateSourceAccountBalance(), updateBalanceFromDestinationAccount(),updateBalanceFromSourceAccount().
Simplified the nested if statements in acceptDate() in TransactionImpl
Merge branch 'Feature_Envy'