Add column named `role` to the `users` table and create `assignments` table`
Verify permission to access the attendance
Add role to the `User` model
Add assignment controller
Insert links to `My assignments` and `Assignments`
Add `Assignment` model
Add spec for the assignment model
Retrieve only students
Move link `I am here` from the students index to attendance index
Set default values for `attended_on` and `user`
Make the date field smaller
Add new views for the `Assignment` controller