Implement search

[davclark]

This should be done after #7. We can start with something simple using Django QuerySets:

https://docs.djangoproject.com/en/1.8/ref/models/querysets/#icontains

[davclark]

If we want to implement fuzzy search, it's supported by PostgreSQL, but integration with Django will be non-trivial:

https://michalcodes4life.wordpress.com/2014/06/03/full-text-search-and-fuzzy-search-with-postgresql-and-django/

See also this rationale behind postgresql being "good enough." In our case, we want to keep things as simple as possible so that it's not hard to administer this application:

http://rachbelaid.com/postgres-full-text-search-is-good-enough/