Switch to "context" from stdlib when 1.8 comes out

[olivere]

We want to switch from "golang.org/x/net/context" to "context" when 1.8 is ready.

[eticzon]

Hi @olivere! Thanks for this awesome lib! I'd like to get involved, if that's OK. 😄 Would you mind if I start with this "admin"-y task first?

[olivere]

@eticzon I'd appreciate support if you're ready to spend some of your time. I agree changing golang.org/x/net/context to context should be pretty straightforward. So if you want, feel free to create a PR. Please do so for v5 first.

[eticzon]

Thanks @olivere! Much appreciated! PR's up as well when you've got time to review.

[olivere]

@eticzon I haven't looked into this recently. But can we also switch away from golang.org/x/net/context/ctxhttp now that we have WithContext(...) in stdlib?

[eticzon]

Good point @olivere. I'll change the calls to ctxhttp then and replace them WithContext(...) alternatives.

[olivere]

Thanks so much for working on this. It's been tagged as 5.0.36 now.