Merge pull request #1369 from MITx/feature/jarv/certificate-restriction

...jangoapps/student/management/commands/cert_restriction.py

...angoapps/student/migrations/0024_add_allow_certificate.py

common/djangoapps/student/models.py

common/djangoapps/student/views.py

...goapps/certificates/management/commands/cert_whitelist.py

...angoapps/certificates/migrations/0014_adding_whitelist.py

lms/djangoapps/certificates/models.py

lms/djangoapps/certificates/queue.py

lms/templates/dashboard.html