Bumping minor version number for hotfix to issue #4
[Refs #5] Adding a test to check for downcasting when using .all()
[Refs #4] Updating travis config to include south in tests, and removing useless cruft that was not used on travis
[Fixes #5] .all() now returns a queryset with subclasses selected
[Fixes #5] .all() now returns a queryset with subclasses selected