Github workflow overrides for Lightning Labs

Expects the following GitHub Secrets:

DOCKER_USERNAME: user to login to DockerHub
DOCKER_API_KEY: password/token to login to DockerHub

.github/workflows/build.yaml

@@ -49,7 +49,7 @@ jobs:
           LATEST_BITCOIN_MAJOR_VERSION=$(find . -type d -maxdepth 1 -not -path '*/\.*' | sort -n | tail -n 1 | cut -c 3-)
           PLATFORMS="linux/amd64"
           PUSH=false
-          REPO=ruimarinho/bitcoin-core
+          REPO=${{ github.repository_owner }}/bitcoin-core
           TAGS=()
 
           if [[ $GITHUB_REF == refs/tags/* ]]; then
@@ -96,17 +96,17 @@ jobs:
 
           echo ::set-output name=build_date::$(date -u +'%Y-%m-%dT%H:%M:%SZ')
           echo ::set-output name=docker_platforms::${PLATFORMS}
-          echo ::set-output name=docker_username::ruimarinho
+          echo ::set-output name=docker_username::${{ secrets.DOCKER_USERNAME }}
           echo ::set-output name=push::${PUSH}
           echo ::set-output name=tags::${TAGS[@]}
           echo ::set-output name=build::true
 
       - if: ${{ steps.prepare.outputs.build }} == 'true'
         name: Login into Docker Hub
-        uses: docker/login-action@v1
+        uses: lightninglabs/gh-actions/login-action@2021.01.25.00
         with:
-          username: ruimarinho
-          password: ${{ secrets.DOCKER_HUB_PASSWORD }}
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_API_KEY }}
 
       - if: ${{ steps.prepare.outputs.build }} == 'true'
         name: Build Docker image
@@ -133,3 +133,8 @@ jobs:
             --build-arg "VCS_REF=${GITHUB_SHA::8}" \
             $(printf "%s" "${TAGS[@]/#/ --tag }" ) \
             ${{ matrix.version }}/
+
+      - if:  ${{ steps.prepare.outputs.build }} == 'true'
+        name: Clear Docker credentials
+        run: |
+          rm -f ${HOME}/.docker/config.json