Add host/group vars

This adds job-level definitions of Ansible host variables and group
variables.

Change-Id: I259144a8560f8fa5ff5990620854fed2002c8951
diff --git a/tests/base.py b/tests/base.py
index 70889bb..96491f9 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -1325,7 +1325,7 @@
                 host['host_vars']['ansible_connection'] = 'local'
 
         hosts.append(dict(
-            name=['localhost'],
+            name='localhost',
             host_vars=dict(ansible_connection='local'),
             host_keys=[]))
         return hosts