Bump codecov/codecov-action from v1.0.14 to v1.0.15

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from v1.0.14 to v1.0.15.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Commits](codecov/codecov-action@v1.0.14...239febf)

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

.github/workflows/CI.yml

@@ -34,7 +34,7 @@ jobs:
       - name: Run tests
         run: ./vendor/bin/phpunit --coverage-clover=coverage.xml
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v1.0.14
+        uses: codecov/codecov-action@v1.0.15
         with:
           file: ./coverage.xml
           token: ${{ secrets.CODECOV_TOKEN }}