feat: Support the ED25519 reference when pointing to the algorithm (#12)

* Backwards compatibility

* try action on ubuntu-22.04

* What about ubuntu-20.04

* Back to ubuntu-latest

Author: anakinj

lib/jwt/eddsa/algo.rb

@@ -7,6 +7,7 @@ module Algo
       include JWT::JWA::SignatureAlgorithm
 
       register_algorithm("EdDSA")
+      register_algorithm("ED25519")
 
       class << self
         def sign(_alg, msg, key)

spec/integration_spec.rb

@@ -17,6 +17,14 @@
       end
     end
 
+    context "when encoding with ED25519" do
+      it "executes successfully" do
+        token = JWT.encode(payload, private_key, "ED25519")
+        expect(JWT.decode(token, public_key, true, algorithm: "EdDSA"))
+          .to eq([payload, { "alg" => "EdDSA" }])
+      end
+    end
+
     context "when decoding key is wrong" do
       let(:public_key) { Ed25519::SigningKey.new("a" * 32).verify_key }
       it "raises decoding error" do