Point html_root_url to docs.rs

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "reqwest"
-version = "0.6.2"
+version = "0.6.2" # remember to update html_root_url
 description = "higher level HTTP client library"
 keywords = ["http", "request", "client"]
 repository = "https://github.com/seanmonstar/reqwest"

src/lib.rs

@@ -1,5 +1,6 @@
 #![deny(warnings)]
 #![deny(missing_docs)]
+#![doc(html_root_url = "https://docs.rs/reqwest/0.6.2")]
 
 //! # reqwest
 //!