tower-service 0.2.0

# 0.2.0 (Dec 12, 2018)

* Change `Service`'s `Request` associated type to be a generic instead.
  * Before:

    ```rust
    impl Service for Client {
        type Request = HttpRequest;
        type Response = HttpResponse;
        // ...
    }
    ```
  * After:

    ```rust
    impl Service<HttpRequest> for Client {
        type Response = HttpResponse;
        // ...
    }
    ```
* Remove `NewService`, use `tower_util::MakeService` instead.
* Remove `Service::ready` and `Ready`, use `tower_util::ServiceExt` instead.

# 0.1.0 (Aug 9, 2018)

* Initial release