Applied the fix of fee round up to the contract code & test script

Author: Sean329

patterns/flash-loans/FlashLoanPool.sol

@@ -48,7 +48,7 @@ contract FlashLoanPool {
         uint256 balanceBefore = token.balanceOf(address(this));
         require(balanceBefore >= borrowAmount, 'too much');
         // Compute the fee, rounded up.
-        uint256 fee = FEE_BPS * (borrowAmount + 1e4-1) / 1e4;
+        uint256 fee = (FEE_BPS * borrowAmount + 1e4-1) / 1e4;
         // Transfer tokens to the borrower contract.
         token.transfer(address(borrower), borrowAmount);
         // Let the borrower do its thing.

test/FlashLoanPool.t.sol

@@ -161,7 +161,7 @@ contract FlashLoanPoolTest is TestUtils, FlashLoanValidator {
     }
 
     function _getFee(uint256 amount) private view returns (uint256) {
-        return pool.FEE_BPS() * (amount + 1e4-1) / 1e4;
+        return (pool.FEE_BPS() * amount + 1e4-1) / 1e4;
     }
 
     function test_canWithdraw() external {