Fix redux plugin type definition

[eatonphil]

Closes #300.

Does this make sense?

[troch]

What's dispatched are actions with type and an optional payload. The payload (when present) can contain a route, previousRoute and optionally a transitionError.

[eatonphil]

@troch not sure what that implies. The Typescript compiler was failing because Dispatch expects to act on an object containing a type field and no type field was declared in the TState type.

[troch]

The initial type signature is incorrect, { router: RouterState } is the type of the reducer output rather than the type of actions dispatched.

Would you mind correcting it as well as adding type?

[eatonphil]

Got it. Look better now?

[troch]

RouterState is not exactly payload. I think actions should be typed like this:

interface Action {
    type: string,
    payload?: {
        route: State
        previousRoute: State | null
        transitionError?: any
    }
}

[eatonphil]

Oh I see. How about now?

[troch]

Thanks 👍