[Request] Add `typings` field to package.json

[TylorS]

First of thanks for taking the time to create and maintain this library!

I was wondering if it would be possible to add the typings field to the package.json in order to allow those who are not using typings to make use of the typescript definitions built with the library. If it would be accepted, I'd gladly make the PR required.

[blakeembrey]

It can't be done because of the dependencies, check the couple of existing issues.