Implement std::io::Write for Vec<'bump, u8>

[marmeladema]

Hi @fitzgen

Here is my attempt to implement std::io::Write for Vec<'bump, u8>
I believe there are other common traits like this we could implement for some collections but I have left that for another time (but I 'd be happy to contribute those).

I have a few questions:

1. The current std feature does not do anything on its own, it's currently only useful if you also have the collections feature enabled too. I think it's fine but I wondered if having instead a collections-std feature depending on collections would be better? Although the std feature is pretty standard across the community.
2. Are there enough tests and are they at the right place? The implementation seems trivial and has been copied from std (except for the vectored part that is currently unstable).

Fixes #215

[fitzgen]

Thanks!

Yeah, it is fine that std without collections doesn't do anything. That's the community norm name and it gives us a place to add any non-collection related std things in the future if it is ever needed.

[fitzgen]

@marmeladema do you need a release with this?

[marmeladema]

If that's not too much to ask, that would be helpful yeah.

[fitzgen]

Just published 3.14.0!

[marmeladema]

Thanks a lot! That's really helpful :-)