Cobra is a package from building cli, its recent release 0.0.4 introduced viper as its dependency and dragged in etcd due to its remote config, so it's time to move away from cobra (can still use spf13/pflags). This makes gommon more self contained (and allow us to reinvent another wheel)

TODO

• chose a package name cc @arrowrowe @gaocegege
• check if I can put a go.mod for cmd/gommon and void the top level go.mod to have spf13/cobra
• required features
  • more flexible command definition, i.e. allow using interface instead of its own struct
  • interactive repl
• survey

Ref

• my notes for reading cobra's source