Release 0.3.0

See #37, release log:

• 2cef1dd by @rultor: version 0.3.0
• b896a41 by @rafamizes: refactor!: restore JsonCacheMe...
• 5351002 by @rafamizes: refactor! rename JsonCacheMem....
• 1f91e76 by @rafamizes: Update README.md
• 9410fad by @rafamizes: Update README.md
• f7ea4fa by @rafamizes: Update README.md
• f7e6711 by @rafamizes: Update README.md
• 8b3f218 by @rafamizes: Update README.md

Released by Rultor 1.70.1, see build log