fix(255): push image to ghcr instead of docker hub

.github/workflows/push.yaml

@@ -11,6 +11,7 @@ env:
   KUBERNETES_VERSION: "1.18.0"
   KIND_VERSION: "0.7.0"
   HELM_REGISTRY_URL: "https://stakater.github.io/stakater-charts"
+  REGISTRY: ghcr.io
 
 jobs:
   build:
@@ -83,11 +84,12 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
 
-      - name: Login to Registry
-        uses: docker/login-action@v1
+      - name: Login to Docker registry ${{env.REGISTRY}}
+        uses: docker/login-action@v1.14.1
         with:
-          username: ${{ secrets.STAKATER_DOCKERHUB_USERNAME }}
-          password: ${{ secrets.STAKATER_DOCKERHUB_PASSWORD }}
+          registry: ${{env.REGISTRY}}
+          username: ${{github.actor}}
+          password: ${{secrets.GITHUB_TOKEN}}
 
       - name: Generate image repository path
         run: |