To run unit tests, run:
pytest defoe
You should see:
============================= test session starts ==============================
platform linux2 -- Python 2.7.13, pytest-3.7.1, py-1.5.4, pluggy-0.7.1
rootdir: /.../<REPOSITORY-DIRECTORY>, inifile
collected 17 items
defoe/test/books/test_archive.py .. [ 11%]
defoe/test/books/test_book.py ........ [ 58%]
defoe/test/books/test_page.py . [ 64%]
defoe/test/papers/test_article.py .. [ 76%]
defoe/test/papers/test_issue.py .... [100%]
========================== 17 passed in 8.62 seconds ===========================