cpath tests, rely more on it

tox.ini

@@ -8,11 +8,12 @@ passenv = CI CI_*
 # deliberately set to nonexistent pathe to check the fallback logic
 setenv = MY_CONFIG = nonexistent
 commands =
-    pip install -e .
+    pip install -e .[testing]
     # TODO ??
     # python -m pytest {posargs}
     python3 -c 'import my.init; from my.config import stub as config; print(config.key)'
     python3 -c 'import my.init; import my.config; import my.config.repos' # shouldn't fail at least
+    python3 -m pytest tests/misc.py tests/get_files.py
     # TODO run demo.py? just make sure with_my is a bit cleverer?
     # TODO e.g. under CI, rely on installing