Oops. Fix blake2 dependency issues.

core/src/pow/mod.rs

@@ -104,6 +104,7 @@ mod test {
 	use super::*;
 	use core::target::Difficulty;
 	use genesis;
+  use consensus::MINIMUM_DIFFICULTY;
 
 	#[test]
 	fn genesis_pow() {

grin/tests/framework.rs

@@ -20,7 +20,7 @@ extern crate grin_api as api;
 extern crate grin_wallet as wallet;
 extern crate secp256k1zkp as secp;
 
-extern crate blake2;
+extern crate blake2_rfc as blake2;;
 extern crate env_logger;
 extern crate futures;
 extern crate tokio_core;