2.1.0

Added

• Add support for Python 3.9
• Add a possibility to append a string to the User-Agent via B2_USER_AGENT_APPEND env

Changed

• Update b2 sync usage text for bucket-to-bucket sync

Removed

• Drop Python 2 support 🎉 (for old systems you can now use the binary distribution)
• Remove --prefix from ls (it didn't really work, use folderName argument)
• Clean up legacy code (CliBucket, etc.)

Fixed

• Fix docs generation in CI
• Correct names of the arguments in b2 create-key usage text