Materials:
-add [OK]
-list [OK]
-delete [OK]

Correction:
-add [problem with files but ok]
-list corrections for students [OK]

-list corrections for professor search [OK]
-show corrections for professor [OK]
-take correction [OK]

Admin:
-Set a student
-Set a corrector

Signed-off-by: Staix34 <kobe.nathan@hotmail.com>