Check page between AJAX requests

While the test should work without this assertion, the intention of the
test is to check what happens if a user selects and investment and, once
it's selected, clicks the "next" link.

spec/features/admin/budget_investments_spec.rb

@@ -1585,6 +1585,8 @@ describe "Admin budget investments" do
 
         within("#budget_investment_#{selected_bi.id}") do
           click_link("Selected")
+
+          expect(page).to have_link "Select"
         end
 
         click_link("Next")