Hide deprecation warning for `hyper::client::Client::handle`
Hide deprecation warning for `hyper::client::Client::handle`

It would be quite cumbersome to quit using the method without breaking
changes. So we continue to use the method in `v0.5.x` branch and remove
the usage in the next minor release.

dmizuk/twitter-stream-rs,d12i/twitter-stream-rs,d12i/twitter-streams-rs