Bump actions/setup-python from v1 to v2.0.1

Bumps [actions/setup-python](https://github.com/actions/setup-python) from v1 to v2.0.1.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v1...807b74f)

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

Author: dependabot[bot]

.github/workflows/build_docs.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Setup Python 3.7
-      uses: actions/setup-python@v1
+      uses: actions/setup-python@v2.0.1
       with:
         python-version: 3.7
     - name: Install dependencies