Pass secret to docker-compose

.github/workflows/run-all-tests.yml

@@ -12,6 +12,8 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - name: Build the docker-compose stack
+        env:
+          DUCKDNS_TOKEN: ${{ secrets.DUCKDNS_TOKEN }}
         run: docker-compose up -d --build
       - name: Run test suite
         run: test/run-all-tests.sh