Fake zuul_connections for gate

We can't establish Gerrit or Github connections in the gate, so
Zuul fails to start.  Reducing the set of connections in the gate
to just smtp should allow it to start (albiet with tenant loading
errors).  But that should let us test basic system setup and
internal connectivity.

Change-Id: I39d648ac5dd6ee3e9bfbc026cd6d7142461c418c

playbooks/zuul/templates/group_vars/zuul.yaml.j2

@@ -1,3 +1,23 @@
+zuul_connections:
+  - name: 'smtp'
+    driver: 'smtp'
+    server: 'localhost'
+    port: '25'
+    default_from: 'zuul@zuul.openstack.org'
+    default_to: 'zuul.reports@zuul.openstack.org'
+
+  - name: 'gerrit'
+    driver: 'git'
+    baseurl: '/tmp'
+
+  - name: 'github'
+    driver: 'git'
+    baseurl: '/tmp'
+
+  - name: 'googlesource'
+    driver: 'git'
+    baseurl: '/tmp'
+
 gearman_client_ssl_key: |
   -----BEGIN PRIVATE KEY-----
   MIIEwAIBADANBgkqhkiG9w0BAQEFAASCBKowggSmAgEAAoIBAQDVr8aQW9tQLmDW

zuul.d/system-config-run.yaml

@@ -679,6 +679,10 @@
       - playbooks/roles/zookeeper/
       - playbooks/roles/install-apt-repo
       - playbooks/roles/zuul
+      - playbooks/zuul/templates/group_vars/zuul
+      - playbooks/zuul/templates/group_vars/zookeeper.yaml
+      - playbooks/zuul/templates/host_vars/zk\d+
+      - playbooks/zuul/templates/host_vars/zuul01.openstack.org
       - testinfra/test_zuul_executor.py
       - testinfra/test_zuul_scheduler.py
       - testinfra/test_zuul_merger.py