Ignore py2-specific tests for py3 and vice versa

Author: gyermolenko

conftest.py

@@ -0,0 +1,10 @@
+import sys
+
+
+def pytest_ignore_collect(path):
+    if sys.version_info[0] > 2:
+        if str(path).endswith("__py2.py"):
+            return True
+    else:
+        if str(path).endswith("__py3.py"):
+            return True