ci: add Docker login and pull job to CI pipeline (#244)

- Add a new job named "testing04" for docker login and pull in ci.yml file.

ref: https://github.com/appleboy/ssh-action/issues/230

.github/workflows/ci.yml

@@ -216,3 +216,32 @@ jobs:
         script: |
           git clone https://appleboy:${{ secrets.TEST_TOKEN }}@github.com/go-training/self-runner.git test_repository
           rm -rf test_repository
+
+  testing04:
+    name: docker login and pull
+    runs-on: ubuntu-latest
+    steps:
+    - name: checkout
+      uses: actions/checkout@v1
+
+    - name: login GitHub Container Registry
+      uses: ./
+      with:
+        host: ${{ secrets.HOST }}
+        username: ${{ secrets.USERNAME }}
+        key: ${{ secrets.KEY }}
+        port: ${{ secrets.PORT }}
+        script_stop: true
+        script: |
+          echo ${{ secrets.GITHUB_TOKEN }} | docker login ghcr.io -u github.actor --password-stdin
+
+    - name: login DockerHub Container Registry
+      uses: ./
+      with:
+        host: ${{ secrets.HOST }}
+        username: ${{ secrets.USERNAME }}
+        key: ${{ secrets.KEY }}
+        port: ${{ secrets.PORT }}
+        script_stop: true
+        script: |
+          echo ${{ secrets.DOCKERHUB_TOKEN }} | docker login -u ${{ secrets.DOCKERHUB_USERNAME }} --password-stdin