switch to tp2 CLI11

Summary: migrating to tp2 version of CLI11. Will delete our local copy in next diff to keep this smaller

Reviewed By: shri-khare

Differential Revision: D29808579

fbshipit-source-id: c7b4cf40a64c9e8804f0eb6c749f36fabdbc79e1

build/fbcode_builder/manifests/fboss

@@ -34,6 +34,7 @@ re2
 python
 yaml-cpp
 libyaml
+CLI11
 
 [shipit.pathmap]
 fbcode/fboss/github = .