Local development environment for widgets preview

1. Execute: npm install
2. Write full absolute path to widgets in widgetsList section of config.json file.
3. Add AppsNgen credentials to user section in the config.json file.
4. Execute: node app.js
5. Browse http://localhost:8879/views/index.html
6. Login using AppsNgen credentials

Tool for AppsNgen widgets development which runs viewer and development sandbox parts.