Fixing tests on PyPy

Author: domdfcoding

tests/test_versions.py

@@ -1,13 +1,20 @@
 # stdlib
 import copy
 import pickle
+import platform
+import sys
 
 # 3rd party
 import pytest
 
 # this package
 from domdf_python_tools.versions import Version, _iter_float, _iter_string, _prep_for_eq
 
+pytestmark = pytest.mark.skipif(
+		condition=sys.version_info <= (3, 6, 1) and platform.python_implementation() == "PyPy",
+		reason="Strange bug in PyPy 7.1.1/3.6.1 on Travis when subclassing from Tuple[int, int, int]"
+		)
+
 
 @pytest.mark.parametrize(
 		"string, expects",