rust 1.31.1 release

Author: pietroalbini

_config.yml

@@ -1,8 +1,8 @@
 name: The Rust Programming Language
-stable: "1.31.0"
-stable_date: "2018-12-06"
-stable_blog: "https://blog.rust-lang.org/2018/11/08/Rust-1.30.1.html"
-stable_full_version: "rustc 1.31.0 (abe02cefd 2018-12-04)"
+stable: "1.31.1"
+stable_date: "2018-12-20"
+stable_blog: "https://blog.rust-lang.org/2018/12/20/Rust-1.31.1.html"
+stable_full_version: "rustc 1.31.1 (b6c32da9b 2018-12-18)"
 beta: "1.32"
 beta_date: "2019-01-18"
 nightly: "1.33"