This is a squashed commit:

- Convert MessageBody to accept Pin in poll_next

- add CHANGES and increase versions aligned to semver

- update crates to accomodate MessageBody Pin change

- fix tests and dependencies

actix-http/src/response.rs

@@ -637,7 +637,7 @@ impl ResponseBuilder {
     /// `ResponseBuilder` can not be used after this call.
     pub fn streaming<S, E>(&mut self, stream: S) -> Response
     where
-        S: Stream<Item = Result<Bytes, E>> + 'static,
+        S: Stream<Item = Result<Bytes, E>> + Unpin + 'static,
         E: Into<Error> + 'static,
     {
         self.body(Body::from_message(BodyStream::new(stream)))