inspection: fix pytest pathlib compat (Python 3.5)

tests/inspection/test_info.py

@@ -28,8 +28,13 @@ def demo_wheel():  # type: () -> Path
 
 
 @pytest.fixture
-def demo_setup(tmp_path):  # type: (Path) -> Path
-    setup_py = tmp_path / "setup.py"
+def source_dir(tmp_path):  # type: (Path) -> Path
+    yield Path(tmp_path.as_posix())
+
+
+@pytest.fixture
+def demo_setup(source_dir):  # type: (Path) -> Path
+    setup_py = source_dir / "setup.py"
     setup_py.write_text(
         decode(
             "from setuptools import setup; "
@@ -38,12 +43,12 @@ def demo_setup(tmp_path):  # type: (Path) -> Path
             'install_requires=["package"])'
         )
     )
-    yield tmp_path
+    yield source_dir
 
 
 @pytest.fixture
-def demo_setup_cfg(tmp_path):  # type: (Path) -> Path
-    setup_cfg = tmp_path / "setup.cfg"
+def demo_setup_cfg(source_dir):  # type: (Path) -> Path
+    setup_cfg = source_dir / "setup.cfg"
     setup_cfg.write_text(
         decode(
             "\n".join(
@@ -57,12 +62,12 @@ def demo_setup_cfg(tmp_path):  # type: (Path) -> Path
             )
         )
     )
-    yield tmp_path
+    yield source_dir
 
 
 @pytest.fixture
-def demo_setup_complex(tmp_path):  # type: (Path) -> Path
-    setup_py = tmp_path / "setup.py"
+def demo_setup_complex(source_dir):  # type: (Path) -> Path
+    setup_py = source_dir / "setup.py"
     setup_py.write_text(
         decode(
             "from setuptools import setup; "
@@ -71,7 +76,7 @@ def demo_setup_complex(tmp_path):  # type: (Path) -> Path
             'install_requires=[i for i in ["package"]])'
         )
     )
-    yield tmp_path
+    yield source_dir
 
 
 @pytest.fixture