frontend/pkgdeps.py: Add python-django to the list of Fedora packages

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
frontend/settings.py: Fix frontend module imports

With the end of (most) import hacks, now the frontend
modules must use the full import path, rather than a
relative path.

This patch fixes the scheduler, broken with the import
changes.

CC: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>