Soon to be integrated into a complete USGS-Astrogeology web service for recieving custom SVG maps.
To preview and interact with the current model, type this in your terminal:
$ git clone https://github.com/louiemontes/scalebarWebService.git
$ cd scalebarWebService
$ npm start
Then go to http://127.0.0.1:3000/ in your browser of choice.