switch to pyre for type checking
switch to pyre for type checking

Reviewed By: vitaut

Differential Revision: D24281813

fbshipit-source-id: 1d1c6280561f76496f36e9a1b3407f4f92658b4b

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift