Fix compatibility issues in tests

Author: RKrahl

.github/requirements.txt

@@ -1,2 +1,3 @@
+pathlib ; python_version == '2.7'
 pytest >=3.7.0
 setuptools_scm

tests/test_09_examples_scope.py

@@ -27,7 +27,7 @@ def test_scope_module(ctestdir):
 def test_scope_session(ctestdir):
     """Dependencies in session scope
     """
-    subdir = Path(ctestdir.tmpdir) / "tests"
+    subdir = Path(str(ctestdir.tmpdir)) / "tests"
     subdir.mkdir()
     with get_example("scope_session_mod_01.py").open("rt") as sf:
         with (subdir / "test_mod_01.py").open("wt") as df: