Refactor the test$()$ method into a new separate thread

$$ In addition to testing the bank at the end of all the transfers, we also want to test it periodically.

Uncomment the line in Bank.transfer that reads: if $($shouldTest$())$ test;

$$ Run the program again and you will notice now that the test method reports an error again.

$$ This is because while the test method is summing the amounts in each account in one thread, transfers are still taking place in other threads. This is the source of another race condition.

$$ To fix this race condition, you must refactor the test$)$ method into a new separate thread

$$ Remember that there is $1$ TestThread, and there are $10$ TransferThreads