[reserved] College enrollment CRUD

[lzrmihnea]

Create submodule in iStudent repo with basic mechanism for College Enrollment
Requirements:

• College Sections CRUD:
  -- Ability to create, read, update, delete a college section (eg: mathematics, computer science, biology, law) with the following fields (name, number of years, max number of students per year)
  -- Ability to create, read, update, delete a college applicant (with lastname, firstname, age and grade of enrollment)
  -- Ability to enlist a college applicant to multiple college sections (with order of preference)
  -- Ability see at any given time which college section has which students

• The students are admitted to a college section based on their grades (descending order)

• If a student does not have a grade good enough for his first college section pick, the application will attempt to add him to his second college section pick (and so on, until he is enrolled to a college section or until he is not enrolled into anything)