Bump to 0.2.1

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 
 name = "gcc"
-version = "0.2.0"
+version = "0.2.1"
 authors = ["Alex Crichton <alex@alexcrichton.com>"]
 license = "MIT/Apache-2.0"
 repository = "https://github.com/alexcrichton/gcc-rs"

src/lib.rs

@@ -42,7 +42,7 @@
 //! }
 //! ```
 
-#![feature(core, io, path, env, collections)]
+#![feature(io, path, env, collections)]
 
 use std::env;
 use std::old_io::{self, Command};
@@ -58,7 +58,7 @@ pub struct Config {
 }
 
 fn getenv(v: &str) -> Option<String> {
-    let r = env::var_string(v).ok();
+    let r = env::var(v).ok();
     println!("{} = {:?}", v, r);
     r
 }