Refactor User model

You should add 3 models that will inherit from User model:
  -  Administrator
  -  Lecturer
  - Student

Add ability to create Students, Lecturer, Administrator.

Also you should add **Controllers** for each User type that will inherit from UsersController. 

Add **routes** for each user type. When Admin go to schedule page, url be must be /administrator/schedule, when Student -- /student/schedule etc.

You shold add something like this to your routes.rb file:
*map.namespace :administrator do |administrator|
   administrator.resource :schedule
         ....
end*