Add devstack base job for zuul v3

This should be managed in the devstack repo, since it's a base job to
run devstack.

Change-Id: Iffe54fbccbccd68db08f79a1b51dd7f76dbff408
Depends-On: Ie2119f24360d56690ffd772b95a9ea6b98dd4a39
diff --git a/roles/fetch-devstack-log-dir/tasks/main.yaml b/roles/fetch-devstack-log-dir/tasks/main.yaml
new file mode 100644
index 0000000..5a198b2
--- /dev/null
+++ b/roles/fetch-devstack-log-dir/tasks/main.yaml
@@ -0,0 +1,5 @@
+- name: Collect devstack logs
+  synchronize:
+    dest: "{{ zuul.executor.log_root }}/{{ inventory_hostname }}"
+    mode: pull
+    src: "{{ devstack_base_dir }}/logs"