put integration code under guard

js/modules/loki_public_chat_api.js

@@ -2,7 +2,6 @@
 const EventEmitter = require('events');
 const nodeFetch = require('node-fetch');
 const LokiAppDotNetAPI = require('./loki_app_dot_net_api');
-const StubAppDotNetAPI = require('../../integration_test/stubs/stub_app_dot_net_api.js');
 
 class LokiPublicChatFactoryAPI extends EventEmitter {
   constructor(ourKey) {
@@ -61,6 +60,7 @@ class LokiPublicChatFactoryAPI extends EventEmitter {
 
       // after verification then we can start up all the pollers
       if (process.env.USE_STUBBED_NETWORK) {
+        const StubAppDotNetAPI = require('../../integration_test/stubs/stub_app_dot_net_api.js');
         thisServer = new StubAppDotNetAPI(this.ourKey, serverUrl);
       } else {
         thisServer = new LokiAppDotNetAPI(this.ourKey, serverUrl);