message: feat(client): implement `Clone` for `http2::SendRequest`
  Closes
diff: @@ -24,6 +24,12 @@ pub struct SendRequest<B> {
  dispatch: dispatch::UnboundedSender<Request<B>, Response<IncomingBody>>,
  }
  +impl<B> Clone for SendRequest<B> {
  + fn clone(&self) -> SendRequest<B> {
  + SendRequest { dispatch: self.dispatch.clone() }
  + }
  +}
  +
  /// A future that processes all HTTP state for the IO object.
  ///
  /// In most cases, this should just be spawned into an executor, so that it
  