Merge pull request #4422 from acozzette/ruby-conformance

Updated Ruby conformance test failure list

conformance/failure_list_ruby.txt

@@ -120,6 +120,8 @@ Required.Proto3.JsonInput.ValueAcceptInteger.JsonOutput
 Required.Proto3.JsonInput.ValueAcceptInteger.ProtobufOutput
 Required.Proto3.JsonInput.ValueAcceptList.JsonOutput
 Required.Proto3.JsonInput.ValueAcceptList.ProtobufOutput
+Required.Proto3.JsonInput.ValueAcceptListWithNull.JsonOutput
+Required.Proto3.JsonInput.ValueAcceptListWithNull.ProtobufOutput
 Required.Proto3.JsonInput.ValueAcceptNull.JsonOutput
 Required.Proto3.JsonInput.ValueAcceptNull.ProtobufOutput
 Required.Proto3.JsonInput.ValueAcceptObject.JsonOutput