Expand travis to compile benchmarks
Benchmark hyper server against rust-http server.

Adds a benchmark for testing the speed of hyper's server.

Due to limitations of rust-http, `cargo bench` now needs to be
killed after running because there is no way to kill a rust-http
server after you start it.
Merge pull request #26 from reem/expand-travis

Expand travis to build docs and run benchmarks
Merge pull request #22 from reem/bench-server

Benchmark hyper server against rust-http server.
Fix server benchmark for Response representation changes.
Merge pull request #28 from reem/fix-server-bench

Fix server benchmark for Response representation changes.