Change incremental link

Author: aturon

_posts/2017-02-06-roadmap.md

@@ -71,7 +71,7 @@ statement links to a corresponding tracker with more details:
 
 * [**Rust should have a pleasant edit-compile-debug cycle**](https://github.com/rust-lang/rust-roadmap/issues/1). Plans
   include
-  [incremental compilation](https://github.com/aturon/rust-roadmap/issues/4) and
+  [incremental compilation](https://blog.rust-lang.org/2016/09/08/incremental.html) and
   a [trait system overhaul](https://github.com/aturon/rust-roadmap/issues/8).
 
 * [**Rust should provide a solid, but basic IDE experience**](https://github.com/rust-lang/rust-roadmap/issues/2). Plans