Merge pull request #158 from hugovk/demock

Use stdlib mock instead of backport package for Python 3.8+

setup.py

@@ -64,7 +64,7 @@
     ],
     extras_require={
         'test': [
-            'mock >= 3.0.0',
+            'mock >= 3.0.0; python_version == "3.7"',
             'pytest',
         ],
     },

tests.py

@@ -16,7 +16,13 @@
 from typing import Optional
 from xml.etree import ElementTree as ET
 
-import mock
+
+if sys.version_info >= (3, 8):
+    from unittest import mock
+else:
+    # unittest.mock in 3.7 is too old to support
+    # all the features used in the test suite
+    import mock
 
 from check_manifest import rmtree