Update the pytest config to make fixtures optional

Author: jeromekelleher

.github/workflows/ci.yml

@@ -103,7 +103,7 @@ jobs:
         run: |
           # We are careful to pull in the minimum dependencies here
           # and only operate on files stored in the repo
-          python -m pytest tests/test_api.py
+          python -m pytest -c /dev/null -p no:sc2ts_fixtures tests/test_api.py
 
   packaging:
     name: Packaging tests

tests/conftest.py

@@ -1 +1,3 @@
-pytest_plugins = ["fixtures"]
+# We keep the fixtures in a separate modules so that the plugin can
+# be excluded when running tests on the bare API
+pytest_plugins = ["sc2ts_fixtures"]