Summary:
`Easing` only has static properties and is never constructed or subclassed, so there doesn't seem to be any reason for it to be a class instead of an object.
as a class, Flow errors about `method-unbinding` on every single use of it.
Changelog: [Internal]
Reviewed By: motiz88
Differential Revision: D33774944
fbshipit-source-id: c0bd2e3d7a78e538f95b88b2b1b12d301c8f590c
Marshall Roch
851e87a1a6