fix: add sls access key to CI.

Author: neverendingqs

.github/workflows/ci.yaml

@@ -39,6 +39,8 @@ jobs:
           # Must match value of `TEST_VAR` in `.env.production`
           cat .serverless/cloudformation-template-update-stack.json | grep cf5bb467-9052-4a34-b318-f6df31644229
         working-directory: examples/simple-express-app
+        env:
+          SERVERLESS_ACCESS_KEY: ${{ secrets.SERVERLESS_ACCESS_KEY }}
 
       - name: publish
         # Only publish (maybe) for one version of Node, and only on 'master'