Feature Request: Add option to import/export pkgmanagers

[kbdharun]

This could be similar to import/export subcommands in Stacks.

kbdharun@vanillaos:~$ apx pkgmanagers
Work with the package managers that are available in apx.

Usage:
  apx pkgmanagers [command]

Available Commands:
  list        List all available package managers.
  new         Create a new package manager.
  rm          Remove the specified package manager.
  show        Show information about the specified package manager.

Flags:
  -h, --help   help for pkgmanagers

Use "apx pkgmanagers [command] --help" for more information about a command.
kbdharun@vanillaos:~$ apx stacks
Work with the stacks that are available in apx.

Usage:
  apx stacks [command]

Available Commands:
  export      Export the specified stack.
  import      Import the specified stack.
  list        List all available stacks.
  new         Create a new stack.
  rm          Remove the specified stack.
  show        Show information about the specified stack.
  update      Update the specified stack.

Flags:
  -h, --help   help for stacks

Use "apx stacks [command] --help" for more information about a command.