Domain Reload test suite isn't run by default #1403

Environment

• Pythonnet version: master@ f2dc8f1

Details

• Running pytest form the root of the repo doesn't run the "Domain reload test suite" (test_domain_reload). Probably broken by moving the test files in New loading based on clr_loader #1373.

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

git checkout f2dc8f19c1dcf3a6735d5d9bdabd83ab69121b88
python setup.py develop
pytest

Workaround: run pytest with the directory where the tests are located: pytest src/domain_tests