closes MBL-10642
test plan:
- in the rails console,
- create an ObserverPairingCode for a student
@student.generate_observer_pairing_code
- read pairing codes for a student
@student.observer_pairing_codes
- generated codes should expire in 1 day
- expired and deleted codes should not be returned
in the above call to read codes
Change-Id: I1c0bf25bca4ef34016cff94ce721e3d339e251e1
Reviewed-on: https://gerrit.instructure.com/152105
Reviewed-by: Matthew Sessions <msessions@instructure.com>
Product-Review: Matthew Sessions <msessions@instructure.com>
QA-Review: Matthew Sessions <msessions@instructure.com>
Tested-by: Jenkins