eth/client: add ws/wss support

[q9f]

EthWorks/ethereum.rb#181

[kurotaky]

Now that I need this feature, I will work on it. ;)

[q9f]

Are you currently working on this @kurotaky ?

[kurotaky]

@q9f I will verify and bring it to release after ETH Global Tokyo this weekend..! 🙏