Bump pytest-runner from 5.2.0 to 5.3.0

Bumps [pytest-runner](https://github.com/pytest-dev/pytest-runner) from 5.2.0 to 5.3.0.
- [Release notes](https://github.com/pytest-dev/pytest-runner/releases)
- [Changelog](https://github.com/pytest-dev/pytest-runner/blob/main/CHANGES.rst)
- [Commits](pytest-dev/pytest-runner@5.2...v5.3.0)

Signed-off-by: dependabot[bot] <support@github.com>

setup.py

@@ -33,7 +33,7 @@
 setup_requires = [
     # Pin pytest-runner to 5.2.0, since 5.3.0 uses `find_namespaces` directive, not supported in
     # Python 2.7
-    'pytest-runner == 5.2.0',
+    'pytest-runner == 5.3.0',
 ]
 
 test_reqs = [