mark all subclass of DefaultTask

Summary: Pull Request resolved: https://github.com/facebookresearch/d2go/pull/303

Reviewed By: mcimpoi

Differential Revision: D37220449

fbshipit-source-id: 04985a4b0129ef37aa42534cdb5f3f8d3f6abf00

d2go/runner/lightning_task.py

@@ -490,6 +490,7 @@ class DefaultTask(pl.LightningModule):
         return self
 
 
+# TODO(T123654122): subclass of DefaultTask will be refactored
 class GeneralizedRCNNTask(DefaultTask):
     @classmethod
     def get_default_cfg(cls):