Removed tutor and reviewer model

core/admin.py

core/migrations/0007_auto_20180105_1136.py

core/models.py

core/permissions.py

core/serializers.py

core/tests/test_access_rights.py

core/tests/test_examlist.py

core/tests/test_factory_and_feedback.py

core/tests/test_functional_views.py

core/tests/test_student_page.py

core/tests/test_student_reviewer_viewset.py

core/tests/test_submissiontypeview.py

core/tests/test_subscription_assignment_service.py

core/tests/test_tutor_api_endpoints.py

core/urls.py

core/views.py

delbert.py

util/factories.py

util/importer.py