Release including certificate key pair authorization

[JoshHayter]

Hi,

I'm currently using a module with a dependency on this package and require authentication with Azure using a certificate key pair rather than a client secret.

Would it be possible to release a tag that includes this work?
3786c93

I'm currently aliasing that commit as 2.1.1 to satisfy the composer dependency and would like not to take that to production.

Thanks for all your work on this module!

Josh