Fix for stability changes

Cargo.toml

@@ -18,3 +18,6 @@ aes_xts = ["openssl-sys/aes_xts"]
 [dependencies.openssl-sys]
 path = "openssl-sys"
 version = "0.2.18"
+
+[dev-dependencies]
+rustc-serialize = "0.2"

src/lib.rs

@@ -1,5 +1,4 @@
-#![feature(unsafe_destructor)]
-#![allow(unstable)]
+#![feature(unsafe_destructor, core, io, std_misc, libc, hash, path, collections)]
 #![crate_name="openssl"]
 #![crate_type="rlib"]
 #![crate_type="dylib"]
@@ -7,7 +6,7 @@
 
 extern crate libc;
 #[cfg(test)]
-extern crate serialize;
+extern crate "rustc-serialize" as serialize;
 
 extern crate "openssl-sys" as ffi;