Bump actions/setup-python from 2.2.2 to 2.3.1

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 2.2.2 to 2.3.1.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v2.2.2...v2.3.1)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Closes #15

Change-Id: If4947b7a0a0daa544d52abc9a52c32d2294d087c
diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index 3a7288f..5295b03 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -16,7 +16,7 @@
     steps:
     - uses: actions/checkout@v2.3.4
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v2.2.2
+      uses: actions/setup-python@v2.3.1
       with:
         python-version: ${{ matrix.python-version }}
     - name: Cache pip