Update layout for zuulv3 syntax

Add an example tenant to layout.yaml to allow zuul-scheduler to start
properly.

Collect additional logs to add in debugging gate failures.

Change-Id: Ic8db52d90716fe8a73afba231ac3a063db2710db
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

files/etc/zuul/config/layout.yaml

@@ -1,8 +1,5 @@
 # This file is generated by Ansible
 #  DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
 #
-pipelines: []
-
-jobs: []
-
-projects: []
+- tenant:
+    name: example

tests/collect-logs.yaml

@@ -12,5 +12,8 @@
         mode: pull
         rsync_opts:
           - "--relative"
-        src: /var/log/zuul
+        src: "{{ item }}"
         verify_host: true
+      with_items:
+        - /etc/zuul
+        - /var/log/zuul