Add txHash lock and requirement of additional input for Payout Script

[Clearwood]

Bounty

Complete work on payout bounty script #33, this bounty should be done after #58
This includes adding the txHash as a lock to prevent payouts and requiring an additional input to pay for the tx fee.
txHash lock: flag to prevent multiple payouts from the same transaction

Scope

• add txHash from receipt into data of contract, use it as lock to prevent payouts based on same hash.
• require additional input to pay for transaction fee

Deliverables

• updated code
• positive and negative tests for additional input
• positive and negative tests for txHash as lock

Funding Circle

Nervos

Bounty Owner/Gardener

<@your github username> as

@Clearwood as Child Chain Dev Lead

Gain for the Role

Roles

bounty gardener: @Clearwood / 15 %
bounty worker: name / share
bounty reviewer: name / share

Gardener checklist

• I have attached one of the size- labels to this bounty
• I have submitted this bounty via http://bounty.leapdao.org/viewform
• I have added this bounty to bounty board here https://github.com/orgs/leapdao/projects/6