Add PingController tests

spec/controllers/ping_controller_spec.rb

@@ -0,0 +1,19 @@
+require 'spec_helper'
+
+describe PingController, type: :controller do
+  describe 'GET #index' do
+
+    subject { get :index }
+
+    it { expect(subject.status).to eq 200 }
+
+    context 'when base is un-plug' do
+
+      before do
+        allow(ActiveRecord::Base).to receive(:connected?).and_return(false)
+      end
+
+      it { expect(subject.status).to eq 500 }
+    end
+  end
+end