add support for private_key_jwt and tls_client_auth
Created by: SteveyblamWork
A recent merge to master added support for tls_client_auth scheme by providing an auth scheme value that would only add the client_id to the request body. The Private Key JWT scheme includes the client_id in the client_assertion and so is not needed in the main request body.
This PR simply returns unaltered params when private_key_jwt is specified as the auth_scheme and adds tls support for v1.4
I have also dropped the INFO/DEBUG from the client spec as it appears to switch between the two depending on the ruby version. I thought this was neater and simpler than writing a complex set of contexts for different versions. Especially considering that the important aspect is the output information rather than the label.