chore: downgrade kustomize guestbook image tag (#73)

Signed-off-by: Alexander Matyushentsev <AMatyushentsev@gmail.com>

kustomize-guestbook/guestbook-ui-deployment.yaml

@@ -14,7 +14,7 @@ spec:
         app: guestbook-ui
     spec:
       containers:
-      - image: gcr.io/heptio-images/ks-guestbook-demo:0.2
+      - image: gcr.io/heptio-images/ks-guestbook-demo:0.1
         name: guestbook-ui
         ports:
         - containerPort: 80