Fetch tox dir and html reports

We need to fetch the html test reports after we run the tests.

Change-Id: If05f1557f7de442efcca40efc67353452de01def

.zuul.yaml

@@ -44,6 +44,7 @@
     parent: devstack-tox-functional-consumer
     description: |
       Base job for shade devstack-based functional tests
+    post-run: playbooks/devstack/post.yaml
     required-projects:
       # These jobs will DTRT when shade triggers them, but we want to make
       # sure stable branches of shade never get cloned by other people,

playbooks/devstack/post.yaml

@@ -0,0 +1,4 @@
+- hosts: all
+  roles:
+    - fetch-tox-output
+    - fetch-subunit-output