Switch to pytest-django.
Refactor Amazon API connection out of model manager into utility function.
Move get_transitively_similar movies from model method to utility function.
Move helper decorators for tests into test package.
Add a more robust set of tests on transitive movie relationships.
Move Amazon API exception handling to utility function.
Add tests on Amazon API connection using mock.
Edit test to assert for new desired behavior of Amazon API getter.
Pass updated unit tests by expecting None when API breaks.
Add tests on model managers.