Add spec for Admin::DashboardController#index (#9523)

spec/controllers/admin/dashboard_controller_spec.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe Admin::DashboardController, type: :controller do
+  describe 'GET #index' do
+    it 'returns 200' do
+      sign_in Fabricate(:user, admin: true)
+      get :index
+
+      expect(response).to have_http_status(200)
+    end
+  end
+end