Auth Wrapper (#1174)

* Auth Wrapper

* Tweak cmd flag

* auth_excludes => auth_exclude

* Make Auth.Excludes variadic

* Use metadata.Get (passes through http and http2 it will go through various case formats)

* fix auth wrapper auth.Auth interface initialisation

Co-authored-by: Asim Aslam <asim@aslam.me>

auth/service/service.go

@@ -37,6 +37,10 @@ func (s *svc) Init(opts ...auth.Option) error {
 	return nil
 }
 
+func (s *svc) Options() auth.Options {
+	return s.options
+}
+
 // Generate a new auth account
 func (s *svc) Generate(id string, opts ...auth.GenerateOption) (*auth.Account, error) {
 	// construct the request