Add placeholder put method for adding users
Add ability to create users (no passwords)
Update UserModel schema to avoid _id and __v
Use UserModel for GET /bodyfat
Add basic login and logout functionality via sessions (unsecured)
Add login view and support for session
Fixes issue #27

Create separate authentication controller
Update addBodyFat to use UserModel

Checks if subdocument has an entry with the date, if not it will add
the new body fat entry
Fixes Issue #29

Refactored the fitness controller and added a user controller
Fixes Issue #30

Controllers now follow [name]-controller.js naming convention
Update server.js to use new controllers
Update settings view to have a save function
Fixes issue #25

Add saveSettings function
Add auth check for saving settings
Add bcrypt
Update users model with password fields
Add salt and hash to password field in user controller
Add storing of password
Fixes Issue #23

Add check for correct password during authentication
Replace 'formatString' with 'formattedDate'