Upload build-wheel-mirror jobs into python specific folder

Because we run multi-node jobs of our wheel-mirror jobs, we need to
hash by the version of python the node is running. Otherwise, both
nodes will upload logs to the same place.

Change-Id: I5557747db0773873a6542c5ebbac25ca4d4c779e
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

playbooks/wheel/post-base.yaml

@@ -1,8 +1,18 @@
 - hosts: all
   tasks:
+    - name: Select python version of build
+      set_fact:
+        wheel_python: "python{{ inventory_hostname[-1] }}"
+
+    - name: Ensure build logs directory exists
+      file:
+        path: "{{ zuul.executor.log_root }}/{{ wheel_python }}"
+        state: directory
+      delegate_to: localhost
+
     - name: Collect build logs
       synchronize:
-        dest: "{{ zuul.executor.work_root }}/logs"
+        dest: "{{ zuul.executor.log_root }}/{{ wheel_python }}"
         mode: pull
         src: ~/logs/
         verify_host: true