Remove unused CryptoKit dependency

This enables building on linux target.

Co-authored-by: Benjamin Babik <work@benjaminbabik.com>

Make seed and public key public

Signed-off-by: Tomasz Pietrek <tomasz@nats.io>

Switch to stable version of base32 library

Signed-off-by: Tomasz Pietrek <tomasz@nats.io>

Fix the license badge