add support file to wait for ajax request for capybara tests

spec/support/wait_for_ajax.rb

@@ -0,0 +1,16 @@
+# spec/support/wait_for_ajax.rb
+module WaitForAjax
+  def wait_for_ajax
+    Timeout.timeout(Capybara.default_wait_time) do
+      loop until finished_all_ajax_requests?
+    end
+  end
+
+  def finished_all_ajax_requests?
+    page.evaluate_script('jQuery.active').zero?
+  end
+end
+
+RSpec.configure do |config|
+  config.include WaitForAjax, type: :feature
+end