Add ping/pong health check

spec/controllers/ping_controller_spec.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe PingController, type: :controller do
+  describe 'index' do
+    it 'returns the wanted page and answer with HTTP Status 200' do
+      get :index
+
+      expect(response).to have_http_status :ok
+    end
+  end
+end