Update deployment to use new version which is multi-arch

So it can run on a Raspberry Pi

Author: dmarkey

demo/config/deployment.yaml

@@ -14,7 +14,7 @@ spec:
     spec:
       containers:
       - name: git-sync
-        image: k8s.gcr.io/git-sync:v3.0.1
+        image: k8s.gcr.io/git-sync:v3.1.3
         volumeMounts:
         - name: markdown
           mountPath: /tmp/git