Enable std and std macros during test builds.

src/lib.rs

@@ -32,6 +32,10 @@
 //! hatred of the Daleks.  Rusty destroys the other Daleks and departs the
 //! ship, determined to track down and bring an end to the Dalek race.
 
+#[cfg(test)]
+#[macro_use]
+extern crate std;
+
 #[cfg(test)]
 extern crate test;