provision/downburst: install bind-utils for host command on centos

Signed-off-by: Kyr Shatskyy <kyrylo.shatskyy@clyso.com>

Author: Kyr Shatskyy

teuthology/provision/downburst.py

@@ -266,7 +266,10 @@ def build_config(self):
         if os_type in ('ubuntu', 'fedora'):
             user_info['packages'].append('python')
         if os_type in ('centos'):
-            user_info['packages'].append('python3-pip')
+            user_info['packages'].extend([
+                'python3-pip',
+                'bind-utils',
+            ])
         user_fd = tempfile.NamedTemporaryFile(delete=False, mode='wt')
         user_str = "#cloud-config\n" + yaml.safe_dump(user_info)
         user_fd.write(user_str)