Do a proper wait for zuul at quickstart

Replace plain timeout with retries over tenant status API

Change-Id: I741f3cdc3a042af9775998c72ce6fb5d9c552f8b

playbooks/quick-start/main.yaml

@@ -44,10 +44,18 @@
       name: Example User
       ssh_key: "{{ ssh_public_key }}"
       http_password: secret
-# TODO(corvus): Fix this for real
-- name: Wait for Zuul to start
-  pause:
-    minutes: 1
+- name: Wait for zuul
+  uri:
+    url: http://localhost:9000/api/tenant/example-tenant/status
+    method: GET
+    return_content: true
+    status_code: 200
+    body_format: json
+  register: result
+  retries: 30
+  delay: 10
+  until: result.status == 200 and result.json["zuul_version"] is defined
+  changed_when: false
 - name: Clone zuul-config
   git:
     repo: http://localhost:8080/zuul-config