docker ci via github actions

      - name: Set up Docker Buildx

        id: buildx

        uses: docker/setup-buildx-action@master

      - name: Cache Docker layers

        uses: actions/cache@v2

        with:

          path: /tmp/.buildx-cache

          key: ${{ runner.os }}-buildx-${{ github.sha }}

          restore-keys: |

          ${{ runner.os }}-buildx-

      - uses: docker/login-action@v1

        with:

          username: ${{ secrets.DOCKER_HUB_USERNAME }}