fix(Cargo.toml): update documentation link

Author: seanmonstar

Cargo.toml

@@ -4,7 +4,7 @@ name = "hyper"
 version = "0.9.0"
 description = "A modern HTTP library."
 readme = "README.md"
-documentation = "http://hyperium.github.io/hyper/hyper/index.html"
+documentation = "http://hyperium.github.io/hyper"
 repository = "https://github.com/hyperium/hyper"
 license = "MIT"
 authors = ["Sean McArthur <[email protected]>",