Adding view engine

Adding an engine for interpreting views. 
Fixing the following error: Error: No default engine was specified and no extension was provided.
   at new View (/root/expressLitter/node_modules/express/lib/view.js:41:42)
   at Function.app.render (/root/expressLitter/node_modules/express/lib/application.js:505:12)
   at ServerResponse.res.render (/root/expressLitter/node_modules/express/lib/response.js:828:7)
   at /root/expressLitter/app.js:12:7
   at callbacks (/root/expressLitter/node_modules/express/lib/router/index.js:164:37)
   at param (/root/expressLitter/node_modules/express/lib/router/index.js:138:11)
   at pass (/root/expressLitter/node_modules/express/lib/router/index.js:145:5)
   at Router._dispatch (/root/expressLitter/node_modules/express/lib/router/index.js:173:5)
   at Object.router (/root/expressLitter/node_modules/express/lib/router/index.js:33:10)
   at next (/root/expressLitter/node_modules/express/node_modules/connect/lib/proto.js:169:15)