Enable strategy parameters

Strategy provides parameters to customize algorithm behavior. End user
could query then specify parameters for their requirements.

Change-Id: Id097db5f6e79c94b57674c8e5d55b06098abf18c
Implements-bp: optimization-threshold

watcher/objects/strategy.py

@@ -31,6 +31,7 @@ class Strategy(base.WatcherObject):
         'name': obj_utils.str_or_none,
         'display_name': obj_utils.str_or_none,
         'goal_id': obj_utils.int_or_none,
+        'parameters_spec': obj_utils.dict_or_none,
     }
 
     @staticmethod