Version bump

Author: Alan Jeffrey

Cargo.toml

@@ -2,7 +2,7 @@
 name = "mozjs_sys"
 description = "System crate for the Mozilla SpiderMonkey JavaScript engine."
 repository = "https://github.com/servo/mozjs/"
-version = "0.51.2"
+version = "0.51.3"
 authors = ["Mozilla"]
 links = "mozjs"
 build = "build.rs"