update earth contract to use prisoners's dilemma

[johannbarbie]

problem

linear game is boring.

solution

introduce prisoners dilemma for trades with this matrix:

payment conditions

• contracts and tests
• reviewer by owners

roles

reviewer: @vrde 20% gardner / worker @johannbarbie 80

[vrde]

The matrix is different:

For the last test we used: GOE => H: 10, M: 3, L: 1, CO2 => H: 100, L: 1

[johannbarbie]

@vrde updated

what i've actually implemented is this:

GOE => H: 10, M: 3, L: 1, CO2 => H: 1000, L: 10

i think it makes more sense, just looking at the numbers (comments in tests)

[vrde]

First prisoner's dilemma™ handshakes using the new contract:

• collaborate (0.4Gt) collaborate: https://testnet.leapdao.org/explorer/tx/0x33e2e8f1451719759cbb42b0ff8d31ac7958d9cc15f27e5a2712ae89d408fc1e
• defect (20Gt) collaborate: https://testnet.leapdao.org/explorer/tx0x2edbb83d6698115fcd8ec343c0b5bbeda45b759b1218f127223bf06df9235fc2
• collaborate (0.4Gt) defect: https://testnet.leapdao.org/explorer/tx/0x91beea6188074bc1b05afe9268e3550ab8f3ba7f349a79d3458475753e6b5504
• defect (20Gt) defect: https://testnet.leapdao.org/explorer/tx/0x3654033b8c77a5dcc25abfdf39dfa66ccc5a86cf20284606be7a54e9356e5f89