CentralizedArbitratorWithAppeal.sol increases appealCost on appeal

[greenlucid]

erc-792/contracts/examples/CentralizedArbitratorWithAppeal.sol

Line 125 in 87bea72

dispute.appealCount++;

Then, a function that uses the incremented appealCount is called to check what the cost is supposed to be.
E.g. Create Dispute: 1e15 ETH
Call Appeal Cost: 1e15 ETH
call appeal{value: 1e15} -> the appealCount gets incremented, appealCost(_disputeID, _extraData) is now 2e15, so reverts with:

[FAIL: InsufficientPayment(1000000000000000 [1e15], 2000000000000000 [2e15])] 

found on a test here: https://github.com/greenlucid/pgtcr/pull/1

[greenlucid]

what i've done locally, is put the appealCount increment after the cost calculation and requires