Summary: Converts the manually authored tests against the JavaScript bindings to TypeScript. This should make authoring UTs a bit more pleasent, but more importantly lets us run typechecking on sample usage of all of the various APIs.
Reviewed By: yungsters
Differential Revision: D45570416
fbshipit-source-id: 44586b4d31fbeae406b388ed336a8305c788b5dd
