Log Message:
devel/guile-gcrypt: Update to version 0.2.0

Changelog:

* Changes in 0.2.0 (since 0.1.0)

** (gcrypt hash) now exposes all the algorithms supported by Libgcrypt
** (guix mac) now exposes all the MAC algorithms, not just HMAC
** (guix hmac) is deprecated in favor of (guix mac)
** Guile-Gcrypt can now be compiled with Guile 2.9 (future 3.0)
** Guile-Gcrypt can now be cross-compiled