Support building with OpenSSL 3.0

[moschlar]

There is #114 but that seems to break building with OpenSSL 1.1.1 so that's probably not the best solution.

@linuxwolf Is there an official position regarding this?

[zandbelt]

see also #103

[zandbelt]

support was added here:
OpenIDC@c345a1a
and is now part of the maintenance fork here:
https://github.com/OpenIDC/cjose/tree/version-0.6.2.x

[moschlar]

Huge thanks @zandbelt - I'll wait for you to finish catching up with outstanding issues/pull requests and then you will probably cut an actual release 0.6.2, right?

[zandbelt]

yes, I'll let you know when that is done (I'm pretty close but I'll give people here some time to kick in)