Collect logs to a subfolder

The logs and ara report generated by zuul are
overwriting some of our log content, so this
patch puts our logs into a subfolder instead.

Change-Id: I28712418fb6db4857dc9f74b2ee8b2fbeb651853

zuul.d/playbooks/post.yml

@@ -52,8 +52,8 @@
 
     - name: Copy logs back to the executor
       synchronize:
-        src: "{{ ansible_user_dir }}/src/{{ current_test_repo }}/logs/"
-        dest: "{{ zuul.executor.log_root }}"
+        src: "{{ ansible_user_dir }}/src/{{ current_test_repo }}/logs"
+        dest: "{{ zuul.executor.log_root }}/"
         mode: pull
       when:
         - logs_folder.stat is defined