CameraRoll callbacks are not idiomatic.

[jtremback]

I noticed that the CameraRoll API uses successCallback, errorCallback instead of callback?: ?(error: ?Error) => void. Seems like it would be a good idea for callback APIs in these modules to be done in the standard way. There are a lot of JS libraries that can deal with this type of callback, and it's a good practice to use existing conventions instead of just inventing new ones.

[ide]

#1232 provides a foundation to address this.

[brentvatne]

Closed in favour of @ide's PR, thanks @jtremback!