Log cachecontrol info by default

This is useful for tracking github cache consumption.

Change-Id: Ic3cb7c82dfbbd00672b7ee3443c0da7f774db3b0
Signed-off-by: Jesse Keating <omgjlk@us.ibm.com>

zuul/ansible/logconfig.py

@@ -105,6 +105,10 @@ _DEFAULT_SERVER_LOGGING_CONFIG = {
             'handlers': ['console'],
             'level': 'WARN',
         },
+        'cachecontrol': {
+            'handlers': ['console'],
+            'level': 'INFO',
+        },
     },
     'root': {'handlers': []},
 }