message: fix(client): return Version errors if unsupported
  If a `Request`'s version is `Http09`, `H2`, or `H2c`, `client.request`
  will return a `hyper::Error::Version`, and a message is logged at
  `error!` level.
  Closes
diff: @@ -24,6 +24,7 @@ use http::request;
  use method::Method;
  use self::pool::{Pool, Pooled};
  use uri::{self, Uri};
  +use version::HttpVersion;
  pub use http::response::Response;
  pub use http::request::Request;
  @@ -139,6 +140,15 @@ where C: Connect,
  type Future = FutureResponse;
  fn call(&self, req: Self::Request) -> Self::Future {
  + match req.version() {
  + HttpVersion::Http10 |
  + HttpVersion::Http11 => (),
  + other => {
  + error!("Request has unsupported version \"{}\"", other);
  + return FutureResponse(Box::new(future::err(::Error::Version)));
  + }
  + }
  +
  let url = req.uri().clone();
  let domain = match uri::scheme_and_authority(&url) {
  Some(uri) => uri,
  