Add missing expectations after refreshing the page

This way we know for sure the page has finished refreshing.

Note that, for now, we aren't adding a check after every call to the
`refresh` method because sometimes the page remains identical after
refreshing. Not sure what we should do in these cases.

spec/system/admin/legislation/questions_spec.rb

@@ -110,9 +110,12 @@ describe "Admin legislation questions", :admin do
       find("#nested_question_options input").set("Changed")
       click_button "Save changes"
 
+      expect(page).to have_content "Question updated successfully"
       expect(page).not_to have_css "#error_explanation"
 
       refresh
+
+      expect(page).not_to have_content "Question updated successfully"
       expect(page).to have_field(field_en[:id], with: "Changed")
     end
 
@@ -136,6 +139,7 @@ describe "Admin legislation questions", :admin do
 
       refresh
 
+      expect(page).not_to have_content "Question updated successfully"
       expect(page).not_to have_field fields_for(:en).first[:id], with: "Yes"
       expect(page).to have_field fields_for(:en).last[:id], with: "No"
     end