v3.0.0

This release supersedes v2.1.0 and brings a new feature and some small code improvements:

• Add support for OpenSSL (#52), by @mchalain
• Fix base32 encoding and decoding of bytes array (#54)
• make is_string_valid_b32 public
• improve code readability

sha256: ff0b9ce208c4c6542a0f1e739cf31978fbf28848c573837c671a6cb7b56b2c12