implement amendment signing for appearance releases

spec/factories/appearance_releases.rb

@@ -32,6 +32,14 @@ FactoryBot.define do
       end
     end
 
+    trait :amendment_signed do
+      amendment_signature do
+        path = Rails.root.join("spec", "fixtures", "files", "signature.png")
+        Rack::Test::UploadedFile.new(path, "image/png")
+      end
+      amendment_signer_name "Amendment Signer"
+    end
+
     trait :minor do
       minor true
       guardian_first_name "Jamie"