Why is there a Promisify function exposed

[lholmquist]

I was looking in the code and i saw that there is a Promisify function attached to the factory object, https://github.com/nodeshift/opossum/blob/master/index.js#L85

I did a search and it isn't actually being used. Was this used at some point or was it just for convenience for someone using this library?

If we aren't using it, perhaps we should remove it?

If we removed it, it would be a semver-major change

@lance thoughts? do you remember why it was there?

[lholmquist]

So it looks like we can remove this, as it was added before Node had its own Promisify utility.

The only concern would be for the browser implementation, but a user could either write their own, or use an existing library that did this.