Enable admin management of curricula
Enable admin management of curricula

This commit adds Curriculum model to Django admin, and makes it possible
for people with proper permissions to view/add/change/delete the
records from within. This is another part that was required by #1228.

pbanaszkiewicz/amy,swcarpentry/amy,pbanaszkiewicz/amy,swcarpentry/amy,pbanaszkiewicz/amy,swcarpentry/amy