Summary: This is a guard to ensure all Flipper built-in packages are declared as peer dependencies. It also removes all of them from nested node_modules after installation to be 100% sure they always loaded from the root folder, because e.g. react can be still installed as a transitive dependency even it is not declared as dependency directly.
Reviewed By: passy
Differential Revision: D27040267
fbshipit-source-id: 1e315a6b280b36ab20778ee261aa386b51d9f964
e7c5a5cc93