Fix variables in GH Actions workflow #24

Author: fwilhe

.github/workflows/push.yml

@@ -12,9 +12,9 @@ jobs:
   push:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@master
+    - uses: actions/checkout@v2
     - name: Run CI
       run: |
-        echo ${{ secrets.DH_PW }} | docker login -u ${{ secrets.DH_USER }} --password-stdin
+        echo ${{ secrets.DOCKERHUB_PASSWORD }} | docker login -u ${{ secrets.DOCKERHUB_USER }} --password-stdin
         docker build -t ppiper/cf-cli:latest .
         docker push ppiper/cf-cli:latest