Fix a typo to fix a link.

Author: alexcrichton

_posts/2016-03-02-Rust-1.7.md

@@ -94,7 +94,7 @@ There were a few small updates to Cargo:
   profiles to pull in dev-dependencies during testing and such.
 
 
-[improvment to build scripts]: https://github.com/rust-lang/cargo/pull/2279 
+[improvement to build scripts]: https://github.com/rust-lang/cargo/pull/2279 
 [modification to the `cargo rustc` subcommand]: https://github.com/rust-lang/cargo/pull/2224 
 
 ### Contributors to 1.7