invoke git-style sub commands only when required

[yausername]

This PR fixes the below issue

Git-style sub commands are invoked if alias is used as an argument.
Example

program
  .command('com')
  .alias('c')
  .action(() => {
    console.log('com called')
  })

$ > node index.js c c
com called

  index-com(1) does not exist, try --help