[beta.12] support passing raw arguments to hooks

When running hooks I would like to pass an argument.

For example, the `app-scripts` package can log debug information when passing the `--debug` argument.

`ionic serve --debug` does not work since the `watch` npm script of `app-scripts` is a hook and not the task itself, hooks don't get params passed to them so I can't run it in debug mode.

See [this code](https://github.com/driftyco/ionic-cli/blob/master/lib/cli.js#L297)

Start at lib/cli.js around line 297 and trace how hooks are invoked when running ionic serve. Check how command-line arguments are handled for the app-scripts watch hook. Done means raw arguments such as --debug reach the hook so the app-scripts package can act on them.

索引モデルが issue の本文から書いたものです。