TODO:

• split subcommands to functions
• write test for init subcommand
  • write test with existing repo
  • with ssh credential
    • ssh-agent
    • specify key
• write test for storage subcommand
  • storage add online
  • storage add directory
  • storage list
• add storage remove command
• add sync subcommand
• add check subcommand
• reorganize cmd option for storage
  • use subcommand
• no commit option