Sharon/hook up auth0

[hesharon]

merge this after #25

• Moved routes in backend/index.js to their respective folders and abstracted multer and some gridfs functions
• Migrated to using envvar rather than dotnet for easier selection and management of environment variables
• Tied up some more loose ends with using current logged in user's information to make api requests
• Update README with instructions on how to create and source the env vars and run the backend and frontend