Add support for roles in zuul

This adds support for Ansible roles in Zuul-managed repos.  It
is currently limited to repos within the same source, which is
something we should fix.

We also plan to add support for roles from Ansible Galaxy in a
future change.

Change-Id: I7af4dc1333db0dcb9d4a8318a4a95b9564cd1dd8
diff --git a/tests/fixtures/config/ansible/main.yaml b/tests/fixtures/config/ansible/main.yaml
index d9868fa..8df99f4 100644
--- a/tests/fixtures/config/ansible/main.yaml
+++ b/tests/fixtures/config/ansible/main.yaml
@@ -6,3 +6,4 @@
           - common-config
         project-repos:
           - org/project
+          - bare-role