Bump codecov/codecov-action from v1.1.0 to v1.2.1 (#227)

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from v1.1.0 to v1.2.1.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/master/CHANGELOG.md)
- [Commits](codecov/codecov-action@v1.1.0...e156083)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/tests.yml

@@ -145,4 +145,4 @@ jobs:
           nox --force-color --session=coverage -- xml
 
       - name: Upload coverage report
-        uses: codecov/codecov-action@v1.1.0
+        uses: codecov/codecov-action@v1.2.1