Make ref_path private in Deployment

Avoid using send in Deployments::AfterCreateService spec

app/models/deployment.rb

@@ -280,12 +280,12 @@ def valid_ref
     errors.add(:ref, _('The branch or tag does not exist'))
   end
+  private
+
   def ref_path
     File.join(environment.ref_path, 'deployments', iid.to_s)
   end
-  private
-
   def legacy_finished_at
     self.created_at if success? && !read_attribute(:finished_at)
   end

spec/services/deployments/after_create_service_spec.rb

@@ -49,7 +49,7 @@
     it 'creates ref' do
       expect_any_instance_of(Repository)
         .to receive(:create_ref)
-        .with(deployment.sha, deployment.send(:ref_path))
+        .with(deployment.sha, "refs/environments/production/deployments/#{deployment.iid}")
       service.execute
     end