Replace ssh-keyscan with host keys from node

Now that we have the host keys of a node in zookeeper, we can drop
ssh-keyscan from zuul and simply write the data to known_hosts.

Change-Id: I7a130a9cb47d0e248b7c5d5e3d576bee58a81d73
Signed-off-by: Paul Belanger <pabelanger@redhat.com>
diff --git a/tests/base.py b/tests/base.py
index 2729233..b72927f 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -802,9 +802,13 @@
     def getHostList(self, args):
         self.log.debug("hostlist")
         hosts = super(RecordingAnsibleJob, self).getHostList(args)
-        for name, d in hosts:
-            d['ansible_connection'] = 'local'
-        hosts.append(('localhost', dict(ansible_connection='local')))
+        for host in hosts:
+            host['host_vars']['ansible_connection'] = 'local'
+
+        hosts.append(dict(
+            name='localhost',
+            host_vars=dict(ansible_connection='local'),
+            host_keys=[]))
         return hosts
 
 
@@ -991,6 +995,7 @@
                     created_time=now,
                     updated_time=now,
                     image_id=None,
+                    host_keys=["fake-key1", "fake-key2"],
                     executor='fake-nodepool')
         data = json.dumps(data)
         path = self.client.create(path, data,