Change validators to use the validator_context

Change InstanceKeys to take a namedtuple for context

util/config/validators/validate_timemachine.py

@@ -9,7 +9,9 @@ class TimeMachineValidator(BaseValidator):
   name = "time-machine"
 
   @classmethod
-  def validate(cls, config, user, user_password, app):
+  def validate(cls, validator_context):
+    config = validator_context.config
+
     if not 'DEFAULT_TAG_EXPIRATION' in config:
       # Old style config
       return