Disable removed translations

After removing a translation while editing another one with invalid data
and sending the form, we were displaying the removed translation to the
user.

We now remove that translation from the form, but we don't remove it
from the database until the form has been sent without errors.

spec/shared/features/translatable.rb

@@ -131,6 +131,30 @@ shared_examples "translatable" do |factory_name, path_name, fields|
       expect(page).not_to have_link "Español"
     end
 
+    scenario "Remove a translation with invalid data", :js do
+      skip("can't have invalid translations") if required_fields.empty?
+
+      field = required_fields.sample
+
+      visit path
+
+      click_link "Español"
+      click_link "Remove language"
+
+      click_link "English"
+      fill_in field_for(field, :en), with: ""
+      click_button update_button_text
+
+      expect(page).to have_css "#error_explanation"
+      expect(page).to have_field(field_for(field, :en), with: "")
+      expect(page).not_to have_link "Español"
+
+      visit path
+      click_link "Español"
+
+      expect(page).to have_field(field_for(field, :es), with: text_for(field, :es))
+    end
+
     scenario 'Change value of a translated field to blank', :js do
       skip("can't have translatable blank fields") if optional_fields.empty?