Configure pytorch-probot (pytorch#24423)

Summary:
Pull Request resolved: pytorch#24423

This enables auto-CC'ing based on labels, see
pytorch#24422

Signed-off-by: Edward Z. Yang <[email protected]>

Test Plan: Imported from OSS

Differential Revision: D16833974

Pulled By: ezyang

fbshipit-source-id: de07ea5f0ade9d5ed2160ce8308cf146321bb354

Author: ezyang

.github/pytorch-probot.yml

@@ -0,0 +1 @@
+tracking_issue: 24422