Use std::io::{Read, Write} for fake::Node

[iredelmeier]

[TheSven73]

Is this perhaps a stepping stone to supporting io::{Read, Write} in this crate's public API? That's a feature plenty of people would like to have, including me :)

[iredelmeier]

@TheSven73 that was part of the idea, yes :)

Currently trying to remember why I didn't merge... Probably an exercise best left until after I've had some sleep, though!