Replace /hub with /.well-known/mercure

[Yggdrasil]

You mentioned in #14 that Mercure has recently changed the hub URL from /hub to /.well-known/mercure (dunglas/mercure#182).

I've made the changes in the source and docs and run the Docker and Kubernetes examples. Both work fine now. I've succesfully run the test suite. This is my first golang commit so forgive me if I forget anything obvious.

I get the linting warnings below but they're all marked with wsl (I use Win10 WSL for development) and already existed on your master/HEAD so I haven't attempted to resolve them:

pkg/broadcaster/broadcaster.go:34:5: expressions should not be cuddled with blocks (wsl)
                                b.Stop()
                                ^
pkg/broadcaster/broadcaster.go:36:4: expressions should not be cuddled with blocks (wsl)
                        b.wg.Done()
                        ^
pkg/broadcaster/broadcaster.go:48:5: expressions should not be cuddled with blocks (wsl)
                                b.Stop()
                                ^
pkg/broadcaster/broadcaster.go:87:3: for statement without condition should never be cuddled (wsl)
                for {
                ^

I'm also not sure if I should commit the go.sum and go.mod files. go.mod has a dozen changes but they're all marked // indirect. Any advice on that?

[jderusse]

Thank you for your contribution. I've created #16 to Fix CS and update go.mod and go.sum files. And #13 to Fix tests.

Could you please rebase your PR?

[Yggdrasil]

Thanks for the swift update. Done!

[jderusse]

Thank you @Yggdrasil