Follow up - 0798e7d - moved from circle ci to github actions. Fixed b…

…ug: Can't use GitHub repository secret as GitHub Actions ENV for `git` checkout command. Migrated to given GITHUB_ACTOR GitHub Action ENV and aliased it to have the possibility to change it in the corresponding workflow YAML (e.g. for testing purposes). There is a workaround needed because aliasing an ENV is not possible.

.github/workflows/build-docker-compose-images.yaml

@@ -13,9 +13,11 @@ jobs:
       DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
       DOCKER_REPOSITORY: "zammad-docker-compose"
       DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
-      REPO_USER: ${{ secrets.REPO_USER }}
     steps:
-      - name: Checkout code
+     - name: Alias GITHUB_ACTOR as REPO_USER
+      run: |
+        echo "::set-env name=REPO_USER::$GITHUB_ACTOR"
+     - name: Checkout code
         uses: actions/checkout@master
       - name: Fetch all history for all tags and branches
         run: git fetch --prune --unshallow

.github/workflows/build-docker-image.yaml

@@ -13,8 +13,10 @@ jobs:
       DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
       DOCKER_REPOSITORY: "zammad"
       DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
-      REPO_USER: ${{ secrets.REPO_USER }}
     steps:
+      - name: Alias GITHUB_ACTOR as REPO_USER
+        run: |
+          echo "::set-env name=REPO_USER::$GITHUB_ACTOR"
       - name: Checkout code
         uses: actions/checkout@master
       - name: Fetch all history for all tags and branches