custom validation today

- add module cheerio into package.json to manage html document such as wit jquery into local enviroment
- add mechanism for validate whole exams report of one day ( start with function validateHtml)
- add POST /setClockAula route into ignore array (row 277 app.js)
- change my custom css for index page
- remove field that is not useful from index.html (for example menu file and login or registered) and add countdown div and button finish (that I still have to manage)
- I manage timer into studentLogin