Clean up register.js

Signed-off-by: tungpham31 <tungpham31@gmail.com>
Consider course permission when registering.

Signed-off-by: tungpham31 <tungpham31@gmail.com>
Update gitignore to ignore .idea files.

Signed-off-by: tungpham31 <tungpham31@gmail.com>
Reindent and reformat files.

Signed-off-by: tungpham31 <tungpham31@gmail.com>
Add interface to get a list of all the courses.

Signed-off-by: tungpham31 <tungpham31@gmail.com>