Typescript definitions incorrect for transitionconfig

[justindmyers]

It looks like the transitionconfig definition is incorrect and is trying to use the StackNavigatorConfig definition from react-navigation which has a different definition for transitionconfig than this library.

Here's the typescript error output from the example given in this repo:

Argument of type '{ transitionConfig: { duration: number; timing: (value: Value | ValueXY, config: TimingAnimationConfig) => CompositeAnimation; }; }' is not assignable to parameter of type 'StackNavigatorConfig'.
    Types of property 'transitionConfig' are incompatible.
        Type '{ duration: number; timing: (value: Value | ValueXY, config: TimingAnimationConfig) => CompositeAnimation; }' is not assignable to type '(transitionProps: NavigationTransitionProps, prevTransitionProps: NavigationTransitionProps, isModal: boolean) => TransitionConfig'.
          Type '{ duration: number; timing: (value: Value | ValueXY, config: TimingAnimationConfig) => CompositeAnimation; }' provides no match for the signature '(transitionProps: NavigationTransitionProps, prevTransitionProps: NavigationTransitionProps, isModal: boolean): TransitionConfig'.ts(2345)345)