fix(setup.cfg): run only test/test_*.py files

Restrict test run to files labeled test_*.py in test directory. Do
not run other test files, e.g. test/registry_tests.py which is run
in its own test suite.

setup.cfg

@@ -1,7 +1,8 @@
 [tool:pytest]
 norecursedirs = .* *.egg build dist docs bin boot core dev etc home lib lib64 media mnt node_modules opt proc root run sbin srv sys tmp usr var venv
 testpaths = ./
-python_files = **/test/*.py test/**.py
+python_files = **/test/test_*.py
+confcutdir = test
 
 [coverage:run]
 branch = True