Make deleted bots still show up when searched for by id

appengine/swarming/server/bot_management.py

Index: appengine/swarming/server/bot_management.py
diff --git a/appengine/swarming/server/bot_management.py b/appengine/swarming/server/bot_management.py
index 562569350f7f674744bf4f78812ea8382dcf008a..baf03aed30ea226ed065958e0806639403c19963 100644
--- a/appengine/swarming/server/bot_management.py
+++ b/appengine/swarming/server/bot_management.py
@@ -161,6 +161,9 @@ class BotInfo(_BotCommon):
       self.BUSY if self.task_id else self.NOT_BUSY
     ]
 
+  # Was the bot deleted.

[M-A Ruel, 2017/01/31 18:45:04]

Don't make it a BooleanProperty, as it implies that the value should be
serialized. In practice it's not the case, so I prefer no change here.

[kjlubick, 2017/01/31 19:04:40]

done.

+  deleted = ndb.BooleanProperty(default=False)
+
   @property
   def id(self):
     return self.key.parent().string_id()