push to heroku to deploy when you create a release in github

heroku_release_github_action.yml

  deploy:
    needs:
      - test
      - lint
    if: "success() && startsWith(github.ref, 'refs/tags/')"
    runs-on: ubuntu-latest

    env:
      HEROKU_API_KEY: ${{ secrets.HEROKU_API_KEY }}
      HEROKU_APP: <heroku app name>

    steps:
      - uses: actions/checkout@v2
      - run: sudo timedatectl set-timezone 'Europe/London'  # or your timezone
      - run: git fetch --unshallow
      - run: git switch master
      - run: git remote add heroku https://heroku:$HEROKU_API_KEY@git.heroku.com/$HEROKU_APP.git
      - run: git push heroku master
      - run: heroku config:set -a $HEROKU_APP RELEASE=`python -c "print('$GITHUB_REF'.split('/')[2])"`