Add unit tests for status/health API endpoints

Closes [SCI-2746].

spec/controllers/api/api_controller_spec.rb

@@ -13,12 +13,31 @@ describe Api::ApiController, type: :controller do
 
     it 'Response with correct JSON status structure' do
       hash_body = nil
-      expect { hash_body = json }.not_to raise_exception
-      expect(hash_body).to match(
-        'message' => I18n.t('api.core.status_ok'),
-        'versions' => [{ 'version' => 'v1',
-                         'baseUrl' => '/api/v1/' }]
-      )
+      expect{hash_body = json}.not_to raise_exception
+      expect(hash_body).to include(:message => I18n.t('api.core.status_ok'))
+      expect(hash_body).to include('versions')
+
+      Extends::API_VERSIONS.each_with_index do |ver, index|
+        expect(hash_body['versions']).to include(
+          { 'version' => ver,
+            'baseUrl' => "/api/#{ver}/" }
+        )
+      end
+    end
+  end
+
+  describe 'GET #health' do
+    before do
+      get :health
+    end
+
+    it 'Returns HTTP success' do
+      expect(response).to be_success
+      expect(response).to have_http_status(200)
+    end
+
+    it 'Response with the correct plain text' do
+      expect(response.body).to match('RUNNING')
     end
   end
 end