Make EIP155 signatures compatible with tester

[pcppcp]

What's wrong

eth-tester has some support for EIP155 that activates replay protection for transactions, but it still doesn't work reliably (i.e. getTransactionByHash still raises errors)

How to fix it

• short term: do not use EIP155 with tests, monkeypatch local signing method to use old-style v in (0, 1, 27 ,28)
• long term: pester eth-tester team to have full support of signatures with v >= 35

[palango]

This should be fixed with ethereum/eth-tester#82

[pcppcp]

yes, I've seen that PR. But it's just a workaround and it can take some time until the change propagates to master and pypi. Correct v validation needs a network id and this would require more changes to the validation.outbound module.

I can patch module's validate_signature_v however, this could be a better solution than replacing signature algo.