Support appending additional arguments

Would it be possible to add the ability to accept additional arguments so I could do something like this:

```
"husky": {
"hooks": {
"post-checkout": "yarnhook --ignore-optional",
"post-merge": "yarnhook --ignore-optional",
"post-rewrite": "yarnhook --ignore-optional"
}
}
```

I'd really like to prevent yarnhook from installing optional dependencies.