submit form directly in tests

app/views/payments/_payment.html.haml

@@ -30,5 +30,5 @@
       %a
         = number_to_currency @total_amount_to_pay
   .form-group
-    = f.submit "Charge Card", class: "btn btn-primary", id: "charge_card"
+    = f.submit "Charge Card", class: "btn btn-primary"
     = link_to "Cancel", conference_conference_registrations_path, class: "btn btn-danger"

spec/features/ticket_purchases_spec.rb

@@ -38,8 +38,7 @@ feature Registration do
         select Date.current.year + 2, from: 'expiration_year'
         fill_in 'card_verification_value', with: '123'
         fill_in 'credit_card_number', with: '4242424242424242'
-
-        click_button 'Charge Card'
+        submit_form
 
         expect(current_path).to eq(conference_conference_registrations_path(conference.short_title))
         payment = Payment.where(user_id: participant.id, conference_id: conference.id).first