Capybara disable animations

Fixes failing specs where animations were preventing modals from
closing.

- purchase_system_spec:99
- purchase_system_spec:255

spec/rails_helper.rb

@@ -45,6 +45,9 @@
 # If an element is hidden, Capybara should ignore it
 Capybara.ignore_hidden_elements = true
 
+# disable CSS transitions and jQuery animations
+Capybara.disable_animation = true
+
 # https://docs.travis-ci.com/user/chrome
 Capybara.register_driver :chrome do |app|
   args = %w[no-sandbox disable-gpu disable-site-isolation-trials window-size=1680,1050]