remove future type param

[hawkw]

No description provided.

[hlb8122]

@hawkw oh ok, I thought it was more embedded than that - you can literally just delete the Fut lines with no problem. >_>

You've probs noticed that that we no longer have the same kind of constraints we do on the other combinator ServiceExt methods.

    fn map_ok<F, Response>(self, f: F) -> MapOk<Self, F>
    where
        Self: Sized,
        F: FnOnce(Self::Response) -> Response + Clone,

    fn map_err<F, Error>(self, f: F) -> MapErr<Self, F>
    where
        Self: Sized,
        F: FnOnce(Self::Error) -> Error + Clone,

https://docs.rs/futures/0.3.8/futures/future/trait.TryFutureExt.html#method.and_then
etc

If you ok with this I'll merge this then get docs done.

[hawkw]

You've probs noticed that that we no longer have the same kind of constraints we do on the other combinator ServiceExt methods.

IMO, that's fine, and I'd move forward on merging this. The map combinators don't take functions that return a future, so they don't need to be generic over its type to introduce this bound. I'd get a second opinion from @LucioFranco when merging your PR, but I think this is okay.