title: Django tests not finding my tests
body: <p>When I run tests, django runs 0 tests. This is my project structure:</p>
  
  <pre><code>manage.py
  - app/
    - main_app/
      - test/
         - tests_v1.py
         - tests_v2.py
  </code></pre>
  
  <p>I use this command:</p>
  
  <pre><code>python manage.py test --pattern="tests_v*.py"
  </code></pre>
  
  <p>Django runs 0 tests in 0 seconds. What am I missing?</p>