Add absolute_import failing SSCCE, and get pytest to ignore it

test/absolute_import/local_module.py

@@ -0,0 +1,13 @@
+"""
+This is a module that imports the *standard library* unittest,
+despite there being a local "unittest" module. It specifies that it
+wants the stdlib one with the ``absolute_import`` __future__ import.
+
+The twisted equivalent of this module is ``twisted.trial._synctest``.
+"""
+from __future__ import absolute_import
+
+import unittest # this is stdlib unittest, but jedi gets the local one
+
+class Assertions(unittest.TestCase):
+    pass