Use importlib_resources to load the local resource.

Author: jaraco

setup.cfg

@@ -43,6 +43,7 @@ testing =
 	pytest-enabler >= 1.3
 
 	# local
+	importlib-resources@git+https://github.com/python/importlib_resources@feature/203-non-package-modules
 
 docs =
 	# upstream

tests/test_officepack.py

@@ -1,13 +1,12 @@
-import pathlib
-
 import pytest
+import importlib_resources as resources
 
 from openpack.officepack import OfficePackage
 
 
 @pytest.fixture
 def officepack_sample(request):
-    return pathlib.Path(__file__).parent.joinpath('empty.docx').open('rb')
+    return resources.files(__name__).joinpath('empty.docx').open('rb')
 
 
 def test_open(officepack_sample):