Support for new Goerli testnet

[holgerd77]

Goerli is a new - currently still experimental - cross-client PoA network, see https://github.com/goerli/testnet for information on network setup, genesis information and bootnodes.

Along with Goerli setup there is also some reactivation and new discussion here ethereum/EIPs#1085 around a common genesis file format. We should actively engage, integrate stuff here (minimally e.g. the terminology) which is settled and contribute with ideas where there is still need for discussion.

Integration here would be a separate issue, generally Goerli support and genesis file format integration is complementary.

[holgerd77]

@vpulim Does this actually need a separate release on the client? Or are all networks/chains automatically supported without further references coming from the common repository?

[holgerd77]

Note: "without further references" should be read along "supported" and not "coming from", so "without further references existing on the client repo". 😄

[vpulim]

All networks are automatically supported so no separate release is needed on the client. You can verify by running client with the --help flag, which will list all known networks.

I will still probably modify the client's package.json to explicitly use version 0.6.1 of common just to make it clear.

[holgerd77]

Yes, that probably makes sense. Eventually also useful to explicitly list the "officially" supported networks in the docs, so that people are aware of what's possible and has been tested to some extend (maybe also add at least one test case to the unit tests for each network? Have no insight if the structure of the tests allow for such level of liveness for test runs.).