Failed to import scrypt.

It seems always show "Failed to import scrypt." at any command.

```
~ $ hydrachain --help

Failed to import scrypt. This is not a fatal error but does
mean that you cannot create or decrypt privkey jsons that use
scrypt

Usage: hydrachain [OPTIONS] COMMAND [ARGS]...

  Welcome to HydraChain/v0.3.2/linux2/py2.7.9
  ...
```

Do you know what's the issue for this?
