node express and session management.

• http://www.webdeveasy.com/single-page-application-authentication
• https://scotch.io/tutorials/implement-oauth-into-your-express-koa-or-hapi-applications-using-grant
• https://www.thepolyglotdeveloper.com/2015/01/session-management-expressjs-web-application/
• Token based authentication (JWT Json Web TOken) https://stormpath.com/blog/token-auth-spa
• Oauth / node.js http://resources.infosecinstitute.com/securing-web-apis-part-ii-creating-an-api-authenticated-with-oauth-2-in-node-js/