Add tooling to store questions in the database

-   ignoring questions.csv so we can download from google drive and process it
    using tools/savequestions.js
-   added public link to google spreadsheet
Add question resource and routes

-   Added the question model for Mongodb
-   Added GET /api/questions, GET /api/questions/:id, PUT and GET
    /api/questions/:id/answer
Fix more stylistic errors