Fix intermittent failures in track tests

Boostrap's off-screen rendering was interfering with finding links
in the page layout.

The included approach should be bulletproof.

spec/features/tracks_spec.rb

@@ -36,8 +36,11 @@ feature Track do
 
       expected = expect do
         visit admin_conference_program_tracks_path(conference_id: conference.short_title)
-
-        click_link 'Delete'
+        within('#tracks', visible: true) do
+          page.accept_confirm do
+            find_link('Delete').click
+          end
+        end
       end
 
       expected.to change { Track.count }.by(-1)
@@ -53,7 +56,9 @@ feature Track do
 
       expected = expect do
         visit admin_conference_program_tracks_path(conference_id: conference.short_title)
-        click_link 'Edit'
+        within('#tracks', visible: true) do
+          find_link('Edit').trigger('click')
+        end
 
         fill_in 'track_name', with: 'Distribution'
         fill_in 'track_short_name', with: 'Distribution'

spec/spec_helper.rb

@@ -59,7 +59,7 @@ RSpec.configure do |config|
   Capybara.javascript_driver = :poltergeist
 
   Capybara.register_driver :poltergeist do |app|
-    Capybara::Poltergeist::Driver.new(app, phantomjs: Phantomjs.path, js_errors: false)
+    Capybara::Poltergeist::Driver.new(app, phantomjs: Phantomjs.path, js_errors: false, window_size: [1920, 1080])
   end
 
   # Includes helpers and connect them to specific types of tests
@@ -82,6 +82,14 @@ RSpec.configure do |config|
   # Types of tests (controller, feature, model) will
   # be inferred from subfolder name
   config.infer_spec_type_from_file_location!
+
+  # Enable this if you like to see what you're debugging
+  # config.after(:example) do |example|
+  #   if example.exception
+  #     save_and_open_screenshot
+  #     save_and_open_page
+  #   end
+  # end
 end
 
 OmniAuth.config.test_mode = true