setup.py: include package data (#39115)

setup.py

@@ -9,9 +9,9 @@ import subprocess
 import distutils
 import distutils.core
 import setuptools
-from distutils.command.sdist import sdist
+from setuptools.command.sdist import sdist
 from glob import glob
-from os.path import splitext, basename, join as pjoin, dirname
+from os.path import splitext, basename, join as pjoin
 import os
 from unittest import TextTestRunner, TestLoader
 import doctest
@@ -97,6 +97,7 @@ setuptools.setup(
     license='GPLv3 or later',
     description='Common API to use all French online payment credit card '
     'processing services',
+    include_package_data=True,
     long_description=io.open(
         os.path.join(
             os.path.dirname(__file__),