Release latest stable tag for release_4_0_0

[RO-29]

Hi, My project uses release tag for all the dependencies, is there any plan to release the stable version of release_4_0_0 branch which has the go modules support

Last stable tag release is of 2018 that too without go mod support

Thanks for looking into it

[Nerzal]

I'm allready using v4.0.0-preview1 for some weeks now. Feels stable, i did not encounter a single error. It's working in production code. Would be happy to have a "stable" release for v4

https://github.com/Nerzal/gocloak/pull/196

[torrayne]

I use Echo and I would like to use v4 but I think we'd need a stable release before it's updated.

[ksegun]

It looks like v4 is using go modules, you will need to deal with the changes

go get github.com/dgrijalva/jwt-go/v4