Move dashboard help spinach test to rspec

https://gitlab.com/gitlab-org/gitlab-ce/issues/23036

features/dashboard/help.feature

-@dashboard
-Feature: Dashboard Help
-  Background:
-    Given I sign in as a user
-    And I visit the "Rake Tasks" help page
-
-  Scenario: The markdown should be rendered correctly
-    Then I should see "Rake Tasks" page markdown rendered
-    And Header "Rebuild project satellites" should have correct ids and links

features/steps/dashboard/help.rb

-class Spinach::Features::DashboardHelp < Spinach::FeatureSteps
-  include SharedAuthentication
-  include SharedPaths
-  include SharedMarkdown
-
-  step 'I visit the help page' do
-    visit help_path
-  end
-
-  step 'I visit the "Rake Tasks" help page' do
-    visit help_page_path("administration/raketasks/maintenance")
-  end
-
-  step 'I should see "Rake Tasks" page markdown rendered' do
-    expect(page).to have_content "Gather information about GitLab and the system it runs on"
-  end
-
-  step 'Header "Rebuild project satellites" should have correct ids and links' do
-    header_should_have_correct_id_and_link(2, 'Check GitLab configuration', 'check-gitlab-configuration', '.documentation')
-  end
-end

spec/features/dashboard/help_spec.rb

+require 'spec_helper'
+
+RSpec.describe 'Dashboard Help', feature: true do
+  before do
+    login_as(:user)
+  end
+
+  it 'renders correctly markdown' do
+    visit help_page_path("administration/raketasks/maintenance")
+
+    expect(page).to have_content('Gather information about GitLab and the system it runs on')
+
+    node = find('.documentation h2 a#user-content-check-gitlab-configuration')
+    expect(node[:href]).to eq '#check-gitlab-configuration'
+    expect(find(:xpath, "#{node.path}/..").text).to eq 'Check GitLab configuration'
+  end
+end