Use golang.org/x/crypto/curve25519

[tv42]

diff --git i/extra25519/extra25519_test.go w/extra25519/extra25519_test.go
index 1e1dbdc..55be8ec 100644
--- i/extra25519/extra25519_test.go
+++ w/extra25519/extra25519_test.go
@@ -9,8 +9,8 @@ import (
        "crypto/rand"
        "testing"

-       "code.google.com/p/go.crypto/curve25519"
        "github.com/agl/ed25519"
+       "golang.org/x/crypto/curve25519"
 )

 func TestCurve25519Conversion(t *testing.T) {

Also, please run gofmt ;)