Add feature test for gitab CI dropdown

spec/features/projects/files/gitlab_ci_yml_dropdown_spec.rb

+require 'spec_helper'
+
+feature 'User wants to add a .gitlab-ci.yml file', feature: true do
+  include WaitForAjax
+
+  before do
+    user = create(:user)
+    project = create(:project)
+    project.team << [user, :master]
+    login_as user
+    visit namespace_project_new_blob_path(project.namespace, project, 'master', file_name: '.gitlab-ci.yml')
+  end
+
+  scenario 'user can see .gitlab-ci.yml dropdown' do
+    expect(page).to have_css('.gitlab-ci-yml-selector')
+  end
+
+  scenario 'user can pick a template from the dropdown', js: true do
+    find('.js-gitlab-ci-yml-selector').click
+    wait_for_ajax
+    within '.gitlab-ci-yml-selector' do
+      find('.dropdown-input-field').set('jekyll')
+      find('.dropdown-content li', text: 'jekyll').click
+    end
+    wait_for_ajax
+
+    expect(page).to have_content('This file is a template, and might need editing before it works on your project')
+    expect(page).to have_content('jekyll build -d test')
+  end
+end